SIL verification failed: Should not have an operand for the opened existential: AMI->getTypeDependentOperands().empty()

[hjyamauchi]

Description

https://ci-external.swift.org/job/swift-main-windows-toolchain/867/consoleText

Reproduction

A build failure on the CI.

Also, a reduced test:

% cat crasher.swift 
struct A {}

protocol P {}
extension P {
    func foo() -> some Sequence<A> {
        EmptyCollection<A>()
    }
}

struct B {
    let p: P
    func bar() {
        for x in p.foo() {}
    }
}
% ~/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/bin/swiftc -O ~/tmp/crasher.swift
error: compile command failed due to signal 6 (use -v to see invocation)
SIL verification failed: Should not have an operand for the opened existential: AMI->getTypeDependentOperands().empty()
Verifying instruction:
     %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self // users: %12, %8, %8, %7
->   %12 = witness_method $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self>, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %4 : $*@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %4; user: %14
     %14 = apply %12<@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
In function:
// B.bar()
// Isolation: unspecified
sil hidden @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[%0: noescape **]
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %21, %29, %28, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self // users: %12, %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self // users: %18, %14, %13, %11, %10
  %10 = alloc_stack $@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self>, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %4 : $*@opened("FBD4C218-B28D-11EF-81E3-BAEE63F10E7B", any P) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %4; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  %18 = witness_method $@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self.Iterator, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %9 : $*@opened("FBD4C632-B28D-11EF-81E3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %9; user: %22
  br bb1                                          // id: %19

bb1:                                              // Preds: bb2 bb0
  %20 = alloc_stack $Optional<A>                  // users: %23, %24, %22
  %21 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("FBD4C9E8-B28D-11EF-81E3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22
  %22 = apply %18<@opened("FBD4C9E8-B28D-11EF-81E3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%20, %21) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %21
  %23 = load %20 : $*Optional<A>                  // user: %25
  dealloc_stack %20 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

bb2(%26 : $A):                                    // Preds: bb1
  br bb1                                          // id: %27

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %28
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %29
  %30 = tuple ()                                  // user: %31
  return %30 : $()                                // id: %31
} // end sil function '$s7crasher1BV3baryyF'

Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.	Program arguments: /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/bin/swift-frontend -frontend -c -primary-file /Users/hiroshi/tmp/crasher.swift -target arm64-apple-macosx14.0 -Xllvm -aarch64-use-tbi -enable-objc-interop -color-diagnostics -O -empty-abi-descriptor -resource-dir /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/lib/swift -module-name crasher -in-process-plugin-server-path /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/lib/swift/host/libSwiftInProcPluginServer.dylib -plugin-path /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/lib/swift/host/plugins -plugin-path /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/local/lib/swift/host/plugins -enable-default-cmo -o /var/folders/ww/kxcj3hm12kd92gcwr9t3y7k40000gq/T/TemporaryDirectory.WYwECW/crasher-1.o
1.	Apple Swift version 6.1-dev (LLVM 0f86f354a7bc883, Swift d3064c5fc64ba06)
2.	Compiling with effective version 5.10
3.	While verifying SIL function "@$s7crasher1BV3baryyF".
 for 'bar()' (at /Users/hiroshi/tmp/crasher.swift:12:5)
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x00000001063112e8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x000000010630f9cc llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x0000000106311944 SignalHandler(int) + 304
3  libsystem_platform.dylib 0x000000018e1f6584 _sigtramp + 56
4  libsystem_pthread.dylib  0x000000018e1c5c20 pthread_kill + 288
5  libsystem_c.dylib        0x000000018e0d2a30 abort + 180
6  swift-frontend           0x000000010181d6f0 swift::SILModule::print(llvm::raw_ostream&, swift::ModuleDecl*, swift::SILOptions const&, bool) const + 0
7  swift-frontend           0x000000010183aa98 swift::SILVisitorBase<(anonymous namespace)::SILVerifier, void>::visitSILBasicBlock(swift::SILBasicBlock*) + 87712
8  swift-frontend           0x00000001018252f8 (anonymous namespace)::SILVerifier::visitSILBasicBlock(swift::SILBasicBlock*) + 28
9  swift-frontend           0x0000000101823a60 (anonymous namespace)::SILVerifier::visitSILFunction(swift::SILFunction*) + 10728
10 swift-frontend           0x000000010181d8a8 swift::SILFunction::verify(swift::CalleeCache*, bool, bool, bool) const + 224
11 swift-frontend           0x0000000101820600 swift::SILModule::verify(swift::CalleeCache*, bool, bool) const + 192
12 swift-frontend           0x00000001018204d8 swift::SILModule::verify(bool, bool) const + 140
13 swift-frontend           0x0000000100a51a04 swift::CompilerInstance::performSILProcessing(swift::SILModule*) + 580
14 swift-frontend           0x00000001007fe1d4 performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 820
15 swift-frontend           0x00000001007fd850 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 656
16 swift-frontend           0x0000000100809de8 withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 160
17 swift-frontend           0x00000001007ff72c performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 716
18 swift-frontend           0x00000001007fedf8 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2328
19 swift-frontend           0x00000001005d3490 swift::mainEntry(int, char const**) + 3100
20 dyld                     0x000000018de3b154 start + 2476
hiroshi@himbp tmp % 

Expected behavior

No crash

Environment

The CI https://ci-external.swift.org/job/swift-main-windows-toolchain.

Also the swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain build from swift.org on macOS.

Additional information

No response

[meg-gupta]

@hjyamauchi Can you please add -Xllvm -sil-verify-all -Xllvm -sil-print-function=s7crasher1BV3baryyF to the command line of your reduced test ? I haven't been able to repro it on my local setup.

[hjyamauchi]

@meg-gupta Here it is:

~/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/bin/swiftc -O crasher.swift -Xfrontend -sil-verify-all -Xllvm -sil-print-function=s7crasher1BV3baryyF

error: compile command failed due to signal 6 (use -v to see invocation)
  *** SIL module after #19, stage Mandatory Diagnostic Passes + Enabling Optimization Passes, pass 4: CapturePromotion (capture-promotion)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %5, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_box ${ var any IteratorProtocol<A> }, var, name "$x$generator" // users: %40, %3
  %3 = begin_borrow [lexical] [var_decl] %2 : ${ var any IteratorProtocol<A> } // users: %39, %4
  %4 = project_box %3 : ${ var any IteratorProtocol<A> }, 0 // users: %26, %17
  %5 = struct_element_addr %0 : $*B, #B.p         // user: %7
  %6 = alloc_stack $any P                         // users: %23, %22, %8, %7
  copy_addr %5 to [init] %6 : $*any P             // id: %7
  %8 = open_existential_addr immutable_access %6 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %12, %12, %11
  %9 = alloc_stack $any Sequence<A>               // users: %21, %20, %13, %11
  // function_ref P.foo()
  %10 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %12
  %11 = init_existential_addr %9 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %8; user: %12
  %12 = apply %10<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%11, %8) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %8
  %13 = open_existential_addr immutable_access %9 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %18, %17, %16, %15, %14
  %14 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %13; users: %19, %18, %15
  copy_addr %13 to [init] %14 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  %16 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %13 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %13; user: %18
  %17 = init_existential_addr %4 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %13; user: %18
  %18 = apply %16<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%17, %14) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %13
  dealloc_stack %14 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %19
  destroy_addr %9 : $*any Sequence<A>             // id: %20
  dealloc_stack %9 : $*any Sequence<A>            // id: %21
  destroy_addr %6 : $*any P                       // id: %22
  dealloc_stack %6 : $*any P                      // id: %23
  br bb1                                          // id: %24

bb1:                                              // Preds: bb2 bb0
  %25 = alloc_stack $Optional<A>                  // users: %32, %31, %29
  %26 = begin_access [modify] [unknown] %4 : $*any IteratorProtocol<A> // users: %30, %27
  %27 = open_existential_addr mutable_access %26 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %29, %29, %28
  %28 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %27 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %27; user: %29
  %29 = apply %28<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%25, %27) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %27
  end_access %26 : $*any IteratorProtocol<A>      // id: %30
  %31 = load [trivial] %25 : $*Optional<A>        // user: %33
  dealloc_stack %25 : $*Optional<A>               // id: %32
  switch_enum %31 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %33

// %34                                            // user: %35
bb2(%34 : $A):                                    // Preds: bb1
  %35 = move_value [var_decl] %34 : $A            // users: %37, %36
  debug_value %35 : $A, let, name "x"             // id: %36
  extend_lifetime %35 : $A                        // id: %37
  br bb1                                          // id: %38

bb3:                                              // Preds: bb1
  end_borrow %3 : ${ var any IteratorProtocol<A> } // id: %39
  destroy_value %2 : ${ var any IteratorProtocol<A> } // id: %40
  %41 = tuple ()                                  // user: %42
  return %41 : $()                                // id: %42
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL module after #20, stage Mandatory Diagnostic Passes + Enabling Optimization Passes, pass 5: AccessEnforcementSelection (access-enforcement-selection)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %5, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_box ${ var any IteratorProtocol<A> }, var, name "$x$generator" // users: %40, %3
  %3 = begin_borrow [lexical] [var_decl] %2 : ${ var any IteratorProtocol<A> } // users: %39, %4
  %4 = project_box %3 : ${ var any IteratorProtocol<A> }, 0 // users: %26, %17
  %5 = struct_element_addr %0 : $*B, #B.p         // user: %7
  %6 = alloc_stack $any P                         // users: %23, %22, %8, %7
  copy_addr %5 to [init] %6 : $*any P             // id: %7
  %8 = open_existential_addr immutable_access %6 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %12, %12, %11
  %9 = alloc_stack $any Sequence<A>               // users: %21, %20, %13, %11
  // function_ref P.foo()
  %10 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %12
  %11 = init_existential_addr %9 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %8; user: %12
  %12 = apply %10<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%11, %8) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %8
  %13 = open_existential_addr immutable_access %9 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %18, %17, %16, %15, %14
  %14 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %13; users: %19, %18, %15
  copy_addr %13 to [init] %14 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  %16 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %13 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %13; user: %18
  %17 = init_existential_addr %4 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %13; user: %18
  %18 = apply %16<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%17, %14) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %13
  dealloc_stack %14 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %19
  destroy_addr %9 : $*any Sequence<A>             // id: %20
  dealloc_stack %9 : $*any Sequence<A>            // id: %21
  destroy_addr %6 : $*any P                       // id: %22
  dealloc_stack %6 : $*any P                      // id: %23
  br bb1                                          // id: %24

bb1:                                              // Preds: bb2 bb0
  %25 = alloc_stack $Optional<A>                  // users: %32, %31, %29
  %26 = begin_access [modify] [static] %4 : $*any IteratorProtocol<A> // users: %30, %27
  %27 = open_existential_addr mutable_access %26 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %29, %29, %28
  %28 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %27 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %27; user: %29
  %29 = apply %28<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%25, %27) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %27
  end_access %26 : $*any IteratorProtocol<A>      // id: %30
  %31 = load [trivial] %25 : $*Optional<A>        // user: %33
  dealloc_stack %25 : $*Optional<A>               // id: %32
  switch_enum %31 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %33

// %34                                            // user: %35
bb2(%34 : $A):                                    // Preds: bb1
  %35 = move_value [var_decl] %34 : $A            // users: %37, %36
  debug_value %35 : $A, let, name "x"             // id: %36
  extend_lifetime %35 : $A                        // id: %37
  br bb1                                          // id: %38

bb3:                                              // Preds: bb1
  end_borrow %3 : ${ var any IteratorProtocol<A> } // id: %39
  destroy_value %2 : ${ var any IteratorProtocol<A> } // id: %40
  %41 = tuple ()                                  // user: %42
  return %41 : $()                                // id: %42
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #45, stage Mandatory Diagnostic Passes + Enabling Optimization Passes, pass 6: AllocBoxToStack (allocbox-to-stack)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %38, %37, %15, %24
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %5
  %4 = alloc_stack $any P                         // users: %21, %20, %6, %5
  copy_addr %3 to [init] %4 : $*any P             // id: %5
  %6 = open_existential_addr immutable_access %4 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %10, %10, %9
  %7 = alloc_stack $any Sequence<A>               // users: %19, %18, %11, %9
  // function_ref P.foo()
  %8 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %10
  %9 = init_existential_addr %7 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %6; user: %10
  %10 = apply %8<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%9, %6) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %6
  %11 = open_existential_addr immutable_access %7 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %16, %15, %14, %13, %12
  %12 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %11; users: %17, %16, %13
  copy_addr %11 to [init] %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %13
  %14 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %11 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11; user: %16
  %15 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %11; user: %16
  %16 = apply %14<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%15, %12) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11
  dealloc_stack %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %17
  destroy_addr %7 : $*any Sequence<A>             // id: %18
  dealloc_stack %7 : $*any Sequence<A>            // id: %19
  destroy_addr %4 : $*any P                       // id: %20
  dealloc_stack %4 : $*any P                      // id: %21
  br bb1                                          // id: %22

bb1:                                              // Preds: bb2 bb0
  %23 = alloc_stack $Optional<A>                  // users: %30, %29, %27
  %24 = begin_access [modify] [static] %2 : $*any IteratorProtocol<A> // users: %28, %25
  %25 = open_existential_addr mutable_access %24 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %27, %27, %26
  %26 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %25 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25; user: %27
  %27 = apply %26<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%23, %25) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25
  end_access %24 : $*any IteratorProtocol<A>      // id: %28
  %29 = load [trivial] %23 : $*Optional<A>        // user: %31
  dealloc_stack %23 : $*Optional<A>               // id: %30
  switch_enum %29 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %31

// %32                                            // user: %33
bb2(%32 : $A):                                    // Preds: bb1
  %33 = move_value [var_decl] %32 : $A            // users: %35, %34
  debug_value %33 : $A, let, name "x"             // id: %34
  extend_lifetime %33 : $A                        // id: %35
  br bb1                                          // id: %36

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %37
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %38
  %39 = tuple ()                                  // user: %40
  return %39 : $()                                // id: %40
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #120, stage Mandatory Diagnostic Passes + Enabling Optimization Passes, pass 22: ConsumeOperatorCopyableAddressesChecker (sil-consume-operator-copyable-addresses-checker)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %38, %37, %15, %24
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %5
  %4 = alloc_stack $any P                         // users: %21, %20, %6, %5
  copy_addr %3 to [init] %4 : $*any P             // id: %5
  %6 = open_existential_addr immutable_access %4 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %10, %10, %9
  %7 = alloc_stack $any Sequence<A>               // users: %19, %18, %11, %9
  // function_ref P.foo()
  %8 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %10
  %9 = init_existential_addr %7 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %6; user: %10
  %10 = apply %8<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%9, %6) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %6
  %11 = open_existential_addr immutable_access %7 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %16, %15, %14, %13, %12
  %12 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %11; users: %17, %16, %13
  copy_addr %11 to [init] %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %13
  %14 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %11 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11; user: %16
  %15 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %11; user: %16
  %16 = apply %14<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%15, %12) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11
  dealloc_stack %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %17
  destroy_addr %7 : $*any Sequence<A>             // id: %18
  dealloc_stack %7 : $*any Sequence<A>            // id: %19
  destroy_addr %4 : $*any P                       // id: %20
  dealloc_stack %4 : $*any P                      // id: %21
  br bb1                                          // id: %22

bb1:                                              // Preds: bb2 bb0
  %23 = alloc_stack $Optional<A>                  // users: %30, %29, %27
  %24 = begin_access [modify] [static] %2 : $*any IteratorProtocol<A> // users: %28, %25
  %25 = open_existential_addr mutable_access %24 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %27, %27, %26
  %26 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %25 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25; user: %27
  %27 = apply %26<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%23, %25) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25
  end_access %24 : $*any IteratorProtocol<A>      // id: %28
  %29 = load [trivial] %23 : $*Optional<A>        // user: %31
  dealloc_stack %23 : $*Optional<A>               // id: %30
  switch_enum %29 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %31

// %32                                            // user: %33
bb2(%32 : $A):                                    // Preds: bb1
  %33 = move_value [var_decl] %32 : $A            // users: %35, %34
  debug_value %33 : $A, let, name "x"             // id: %34
  extend_lifetime %33 : $A                        // id: %35
  br bb1                                          // id: %36

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %37
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %38
  %39 = tuple ()                                  // user: %40
  return %39 : $()                                // id: %40
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #123, stage Mandatory Diagnostic Passes + Enabling Optimization Passes, pass 25: MoveOnlyTypeEliminator (sil-move-only-type-eliminator)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %36, %35, %15, %24
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %5
  %4 = alloc_stack $any P                         // users: %21, %20, %6, %5
  copy_addr %3 to [init] %4 : $*any P             // id: %5
  %6 = open_existential_addr immutable_access %4 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %10, %10, %9
  %7 = alloc_stack $any Sequence<A>               // users: %19, %18, %11, %9
  // function_ref P.foo()
  %8 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %10
  %9 = init_existential_addr %7 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %6; user: %10
  %10 = apply %8<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%9, %6) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %6
  %11 = open_existential_addr immutable_access %7 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %16, %15, %14, %13, %12
  %12 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %11; users: %17, %16, %13
  copy_addr %11 to [init] %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %13
  %14 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %11 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11; user: %16
  %15 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %11; user: %16
  %16 = apply %14<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%15, %12) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11
  dealloc_stack %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %17
  destroy_addr %7 : $*any Sequence<A>             // id: %18
  dealloc_stack %7 : $*any Sequence<A>            // id: %19
  destroy_addr %4 : $*any P                       // id: %20
  dealloc_stack %4 : $*any P                      // id: %21
  br bb1                                          // id: %22

bb1:                                              // Preds: bb2 bb0
  %23 = alloc_stack $Optional<A>                  // users: %30, %29, %27
  %24 = begin_access [modify] [static] %2 : $*any IteratorProtocol<A> // users: %28, %25
  %25 = open_existential_addr mutable_access %24 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %27, %27, %26
  %26 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %25 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25; user: %27
  %27 = apply %26<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%23, %25) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25
  end_access %24 : $*any IteratorProtocol<A>      // id: %28
  %29 = load [trivial] %23 : $*Optional<A>        // user: %31
  dealloc_stack %23 : $*Optional<A>               // id: %30
  switch_enum %29 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %31

// %32                                            // user: %33
bb2(%32 : $A):                                    // Preds: bb1
  debug_value %32 : $A, let, name "x"             // id: %33
  br bb1                                          // id: %34

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %35
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %36
  %37 = tuple ()                                  // user: %38
  return %37 : $()                                // id: %38
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #183, stage Mandatory Diagnostic Passes + Enabling Optimization Passes, pass 34: DiagnoseUnreachable (diagnose-unreachable)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %36, %35, %15, %24
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %5
  %4 = alloc_stack $any P                         // users: %21, %20, %6, %5
  copy_addr %3 to [init] %4 : $*any P             // id: %5
  %6 = open_existential_addr immutable_access %4 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %10, %10, %9
  %7 = alloc_stack $any Sequence<A>               // users: %19, %18, %11, %9
  // function_ref P.foo()
  %8 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %10
  %9 = init_existential_addr %7 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %6; user: %10
  %10 = apply %8<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%9, %6) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %6
  %11 = open_existential_addr immutable_access %7 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %16, %15, %14, %13, %12
  %12 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %11; users: %17, %16, %13
  copy_addr %11 to [init] %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %13
  %14 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %11 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11; user: %16
  %15 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %11; user: %16
  %16 = apply %14<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%15, %12) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11
  dealloc_stack %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %17
  destroy_addr %7 : $*any Sequence<A>             // id: %18
  dealloc_stack %7 : $*any Sequence<A>            // id: %19
  destroy_addr %4 : $*any P                       // id: %20
  dealloc_stack %4 : $*any P                      // id: %21
  br bb1                                          // id: %22

bb1:                                              // Preds: bb2 bb0
  %23 = alloc_stack $Optional<A>                  // users: %30, %29, %27
  %24 = begin_access [modify] [static] %2 : $*any IteratorProtocol<A> // users: %28, %25
  %25 = open_existential_addr mutable_access %24 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %27, %27, %26
  %26 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %25 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25; user: %27
  %27 = apply %26<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%23, %25) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %25
  end_access %24 : $*any IteratorProtocol<A>      // id: %28
  %29 = load [trivial] %23 : $*Optional<A>        // user: %31
  dealloc_stack %23 : $*Optional<A>               // id: %30
  switch_enum %29 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %31

// %32                                            // user: %33
bb2(%32 : $A):                                    // Preds: bb1
  debug_value %32 : $A, let, name "x"             // id: %33
  br bb1                                          // id: %34

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %35
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %36
  %37 = tuple ()                                  // user: %38
  return %37 : $()                                // id: %38
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL module after #13, stage PrepareOptimizationPasses, pass 3: AccessMarkerElimination (access-marker-elim)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %24, %34, %33, %15
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %5
  %4 = alloc_stack $any P                         // users: %21, %20, %6, %5
  copy_addr %3 to [init] %4 : $*any P             // id: %5
  %6 = open_existential_addr immutable_access %4 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %10, %10, %9
  %7 = alloc_stack $any Sequence<A>               // users: %19, %18, %11, %9
  // function_ref P.foo()
  %8 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %10
  %9 = init_existential_addr %7 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %6; user: %10
  %10 = apply %8<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%9, %6) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %6
  %11 = open_existential_addr immutable_access %7 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %16, %15, %14, %13, %12
  %12 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %11; users: %17, %16, %13
  copy_addr %11 to [init] %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %13
  %14 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %11 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11; user: %16
  %15 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %11; user: %16
  %16 = apply %14<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%15, %12) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %11
  dealloc_stack %12 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %17
  destroy_addr %7 : $*any Sequence<A>             // id: %18
  dealloc_stack %7 : $*any Sequence<A>            // id: %19
  destroy_addr %4 : $*any P                       // id: %20
  dealloc_stack %4 : $*any P                      // id: %21
  br bb1                                          // id: %22

bb1:                                              // Preds: bb2 bb0
  %23 = alloc_stack $Optional<A>                  // users: %28, %27, %26
  %24 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %26, %26, %25
  %25 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %24 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %24; user: %26
  %26 = apply %25<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%23, %24) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %24
  %27 = load [trivial] %23 : $*Optional<A>        // user: %29
  dealloc_stack %23 : $*Optional<A>               // id: %28
  switch_enum %27 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %29

// %30                                            // user: %31
bb2(%30 : $A):                                    // Preds: bb1
  debug_value %30 : $A, let, name "x"             // id: %31
  br bb1                                          // id: %32

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %33
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %34
  %35 = tuple ()                                  // user: %36
  return %35 : $()                                // id: %36
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #39, stage EarlyModulePasses, pass 1: TempRValueOpt (temp-rvalue-opt)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %30, %29, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %14, %13, %12, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %24, %23, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22, %21
  %21 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %20 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load [trivial] %19 : $*Optional<A>        // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

// %26                                            // user: %27
bb2(%26 : $A):                                    // Preds: bb1
  debug_value %26 : $A, let, name "x"             // id: %27
  br bb1                                          // id: %28

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %29
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %30
  %31 = tuple ()                                  // user: %32
  return %31 : $()                                // id: %32
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #40, stage EarlyModulePasses, pass 2: ComputeSideEffects (compute-side-effects)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %30, %29, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %14, %13, %12, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %24, %23, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22, %21
  %21 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %20 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load [trivial] %19 : $*Optional<A>        // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

// %26                                            // user: %27
bb2(%26 : $A):                                    // Preds: bb1
  debug_value %26 : $A, let, name "x"             // id: %27
  br bb1                                          // id: %28

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %29
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %30
  %31 = tuple ()                                  // user: %32
  return %31 : $()                                // id: %32
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL module after #51, stage EarlyModulePasses, pass 7: PerformanceSILLinker (performance-linker)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %30, %29, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %14, %13, %12, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %24, %23, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22, %21
  %21 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %20 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load [trivial] %19 : $*Optional<A>        // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

// %26                                            // user: %27
bb2(%26 : $A):                                    // Preds: bb1
  debug_value %26 : $A, let, name "x"             // id: %27
  br bb1                                          // id: %28

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %29
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %30
  %31 = tuple ()                                  // user: %32
  return %31 : $()                                // id: %32
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #454, stage HighLevel,Function+EarlyLoopOpt, pass 5: DCE (dce)
// B.bar()
// Isolation: unspecified
sil hidden [ossa] @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %29, %28, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %14, %13, %12, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %24, %23, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22, %21
  %21 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %20 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load [trivial] %19 : $*Optional<A>        // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

bb2(%26 : $A):                                    // Preds: bb1
  br bb1                                          // id: %27

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %28
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %29
  %30 = tuple ()                                  // user: %31
  return %30 : $()                                // id: %31
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #472, stage HighLevel,Function+EarlyLoopOpt, pass 25: NonTransparentFunctionOwnershipModelEliminator (non-transparent-func-ownership-model-eliminator)
// B.bar()
// Isolation: unspecified
sil hidden @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %29, %28, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %14, %13, %12, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %23, %24, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22, %21
  %21 = witness_method $@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %20 : $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load %19 : $*Optional<A>                  // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

bb2(%26 : $A):                                    // Preds: bb1
  br bb1                                          // id: %27

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %28
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %29
  %30 = tuple ()                                  // user: %31
  return %30 : $()                                // id: %31
} // end sil function '$s7crasher1BV3baryyF'

  *** SIL function after  #478, stage HighLevel,Function+EarlyLoopOpt, pass 31: SILCombine (sil-combine)
// B.bar()
// Isolation: unspecified
sil hidden @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %29, %28, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %12, %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %21, %14, %13, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %4 : $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %4; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %23, %24, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22
  %21 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %9; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load %19 : $*Optional<A>                  // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

bb2(%26 : $A):                                    // Preds: bb1
  br bb1                                          // id: %27

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %28
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %29
  %30 = tuple ()                                  // user: %31
  return %30 : $()                                // id: %31
} // end sil function '$s7crasher1BV3baryyF'

SIL verification failed: Should not have an operand for the opened existential: AMI->getTypeDependentOperands().empty()
Verifying instruction:
     %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %12, %8, %8, %7
->   %12 = witness_method $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %4 : $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %4; user: %14
     %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
In function:
// B.bar()
// Isolation: unspecified
sil hidden @$s7crasher1BV3baryyF : $@convention(method) (@in_guaranteed B) -> () {
[global: read,write,copy,destroy,allocate,deinit_barrier]
// %0 "self"                                      // users: %3, %1
bb0(%0 : $*B):
  debug_value %0 : $*B, let, name "self", argno 1, expr op_deref // id: %1
  %2 = alloc_stack [lexical] [var_decl] $any IteratorProtocol<A>, var, name "$x$generator", type $any IteratorProtocol<A> // users: %20, %29, %28, %13
  %3 = struct_element_addr %0 : $*B, #B.p         // user: %4
  %4 = open_existential_addr immutable_access %3 : $*any P to $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self // users: %12, %8, %8, %7
  %5 = alloc_stack $any Sequence<A>               // users: %17, %16, %9, %7
  // function_ref P.foo()
  %6 = function_ref @$s7crasher1PPAAE3fooQryF : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // user: %8
  %7 = init_existential_addr %5 : $*any Sequence<A>, $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self> // type-defs: %4; user: %8
  %8 = apply %6<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>(%7, %4) : $@convention(method) <τ_0_0 where τ_0_0 : P> (@in_guaranteed τ_0_0) -> @out EmptyCollection<A> // type-defs: %4
  %9 = open_existential_addr immutable_access %5 : $*any Sequence<A> to $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // users: %21, %14, %13, %11, %10
  %10 = alloc_stack $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // type-defs: %9; users: %15, %14, %11
  copy_addr %9 to [init] %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %11
  %12 = witness_method $@_opaqueReturnTypeOf("$s7crasher1PPAAE3fooQryF", 0) __<@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self>, #Sequence.makeIterator : <Self where Self : Sequence> (__owned Self) -> () -> Self.Iterator, %4 : $*@opened("C8A844B6-B290-11EF-A9D3-BAEE63F10E7B", any P) Self : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %4; user: %14
  %13 = init_existential_addr %2 : $*any IteratorProtocol<A>, $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator // type-defs: %9; user: %14
  %14 = apply %12<@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self>(%13, %10) : $@convention(witness_method: Sequence) <τ_0_0 where τ_0_0 : Sequence> (@in τ_0_0) -> @out τ_0_0.Iterator // type-defs: %9
  dealloc_stack %10 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self // id: %15
  destroy_addr %5 : $*any Sequence<A>             // id: %16
  dealloc_stack %5 : $*any Sequence<A>            // id: %17
  br bb1                                          // id: %18

bb1:                                              // Preds: bb2 bb0
  %19 = alloc_stack $Optional<A>                  // users: %23, %24, %22
  %20 = open_existential_addr mutable_access %2 : $*any IteratorProtocol<A> to $*@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self // users: %22, %22
  %21 = witness_method $@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self.Iterator, #IteratorProtocol.next : <Self where Self : IteratorProtocol> (inout Self) -> () -> Self.Element?, %9 : $*@opened("C8A84858-B290-11EF-A9D3-BAEE63F10E7B", any Sequence<A>) Self : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %9; user: %22
  %22 = apply %21<@opened("C8A84BAA-B290-11EF-A9D3-BAEE63F10E7B", any IteratorProtocol<A>) Self>(%19, %20) : $@convention(witness_method: IteratorProtocol) <τ_0_0 where τ_0_0 : IteratorProtocol> (@inout τ_0_0) -> @out Optional<τ_0_0.Element> // type-defs: %20
  %23 = load %19 : $*Optional<A>                  // user: %25
  dealloc_stack %19 : $*Optional<A>               // id: %24
  switch_enum %23 : $Optional<A>, case #Optional.some!enumelt: bb2, case #Optional.none!enumelt: bb3 // id: %25

bb2(%26 : $A):                                    // Preds: bb1
  br bb1                                          // id: %27

bb3:                                              // Preds: bb1
  destroy_addr %2 : $*any IteratorProtocol<A>     // id: %28
  dealloc_stack %2 : $*any IteratorProtocol<A>    // id: %29
  %30 = tuple ()                                  // user: %31
  return %30 : $()                                // id: %31
} // end sil function '$s7crasher1BV3baryyF'

Please submit a bug report (https://swift.org/contributing/#reporting-bugs) and include the crash backtrace.
Stack dump:
0.	Program arguments: /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/bin/swift-frontend -frontend -c -primary-file crasher.swift -target arm64-apple-macosx14.0 -Xllvm -aarch64-use-tbi -enable-objc-interop -O -sil-verify-all -empty-abi-descriptor -resource-dir /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/lib/swift -Xllvm -sil-print-function=s7crasher1BV3baryyF -module-name crasher -in-process-plugin-server-path /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/lib/swift/host/libSwiftInProcPluginServer.dylib -plugin-path /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/lib/swift/host/plugins -plugin-path /Users/hiroshi/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-2024-11-20-a.xctoolchain/usr/local/lib/swift/host/plugins -enable-default-cmo -o /var/folders/ww/kxcj3hm12kd92gcwr9t3y7k40000gq/T/TemporaryDirectory.h1O4Xk/crasher-1.o
1.	Apple Swift version 6.1-dev (LLVM 0f86f354a7bc883, Swift d3064c5fc64ba06)
2.	Compiling with effective version 5.10
3.	While evaluating request ExecuteSILPipelineRequest(Run pipelines { PrepareOptimizationPasses, EarlyModulePasses, HighLevel,Function+EarlyLoopOpt, HighLevel,Module+StackPromote, MidLevel,Function, ClosureSpecialize, LowLevel,Function, LateLoopOpt, SIL Debug Info Generator } on SIL for crasher)
4.	While running pass #478 SILFunctionTransform "SILCombine" on SILFunction "@$s7crasher1BV3baryyF".
 for 'bar()' (at crasher.swift:12:5)
5.	While verifying SIL function "@$s7crasher1BV3baryyF".
 for 'bar()' (at crasher.swift:12:5)
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  swift-frontend           0x0000000108c2d2e8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 56
1  swift-frontend           0x0000000108c2b9cc llvm::sys::RunSignalHandlers() + 112
2  swift-frontend           0x0000000108c2d944 SignalHandler(int) + 304
3  libsystem_platform.dylib 0x000000018e1f6584 _sigtramp + 56
4  libsystem_pthread.dylib  0x000000018e1c5c20 pthread_kill + 288
5  libsystem_c.dylib        0x000000018e0d2a30 abort + 180
6  swift-frontend           0x00000001041396f0 swift::SILModule::print(llvm::raw_ostream&, swift::ModuleDecl*, swift::SILOptions const&, bool) const + 0
7  swift-frontend           0x0000000104156a98 swift::SILVisitorBase<(anonymous namespace)::SILVerifier, void>::visitSILBasicBlock(swift::SILBasicBlock*) + 87712
8  swift-frontend           0x00000001041412f8 (anonymous namespace)::SILVerifier::visitSILBasicBlock(swift::SILBasicBlock*) + 28
9  swift-frontend           0x000000010413fa60 (anonymous namespace)::SILVerifier::visitSILFunction(swift::SILFunction*) + 10728
10 swift-frontend           0x00000001041398a8 swift::SILFunction::verify(swift::CalleeCache*, bool, bool, bool) const + 224
11 swift-frontend           0x0000000103b8dbe4 swift::SILPassManager::runPassOnFunction(unsigned int, swift::SILFunction*) + 2544
12 swift-frontend           0x0000000103b8e600 swift::SILPassManager::runFunctionPasses(unsigned int, unsigned int) + 1060
13 swift-frontend           0x0000000103b8b6b8 swift::SILPassManager::executePassPipelinePlan(swift::SILPassPipelinePlan const&) + 72
14 swift-frontend           0x0000000103b8b638 swift::ExecuteSILPipelineRequest::evaluate(swift::Evaluator&, swift::SILPipelineExecutionDescriptor) const + 68
15 swift-frontend           0x0000000103bdc138 swift::SimpleRequest<swift::ExecuteSILPipelineRequest, std::__1::tuple<> (swift::SILPipelineExecutionDescriptor), (swift::RequestFlags)1>::evaluateRequest(swift::ExecuteSILPipelineRequest const&, swift::Evaluator&) + 28
16 swift-frontend           0x0000000103ba850c swift::ExecuteSILPipelineRequest::OutputType swift::Evaluator::getResultUncached<swift::ExecuteSILPipelineRequest, swift::ExecuteSILPipelineRequest::OutputType swift::evaluateOrFatal<swift::ExecuteSILPipelineRequest>(swift::Evaluator&, swift::ExecuteSILPipelineRequest)::'lambda'()>(swift::ExecuteSILPipelineRequest const&, swift::ExecuteSILPipelineRequest::OutputType swift::evaluateOrFatal<swift::ExecuteSILPipelineRequest>(swift::Evaluator&, swift::ExecuteSILPipelineRequest)::'lambda'()) + 204
17 swift-frontend           0x0000000103b8b894 swift::executePassPipelinePlan(swift::SILModule*, swift::SILPassPipelinePlan const&, bool, swift::irgen::IRGenModule*) + 64
18 swift-frontend           0x0000000103bbe36c swift::runSILOptimizationPasses(swift::SILModule&) + 156
19 swift-frontend           0x000000010336da3c swift::CompilerInstance::performSILProcessing(swift::SILModule*) + 636
20 swift-frontend           0x000000010311a1d4 performCompileStepsPostSILGen(swift::CompilerInstance&, std::__1::unique_ptr<swift::SILModule, std::__1::default_delete<swift::SILModule>>, llvm::PointerUnion<swift::ModuleDecl*, swift::SourceFile*>, swift::PrimarySpecificPaths const&, int&, swift::FrontendObserver*) + 820
21 swift-frontend           0x0000000103119850 swift::performCompileStepsPostSema(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 656
22 swift-frontend           0x0000000103125de8 withSemanticAnalysis(swift::CompilerInstance&, swift::FrontendObserver*, llvm::function_ref<bool (swift::CompilerInstance&)>, bool) + 160
23 swift-frontend           0x000000010311b72c performCompile(swift::CompilerInstance&, int&, swift::FrontendObserver*) + 716
24 swift-frontend           0x000000010311adf8 swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*, swift::FrontendObserver*) + 2328
25 swift-frontend           0x0000000102eef490 swift::mainEntry(int, char const**) + 3100
26 dyld                     0x000000018de3b154 start + 2476

[hjyamauchi]

This reproduces with the swift-DEVELOPMENT-SNAPSHOT-2024-04-13-a build from swift.org. So it doesn't seem like a recently-introduced compiler bug if it's a compiler bug.

[compnerd]

Seeing this on Linux as well: https://ci.swift.org/job/swift-PR-Linux-smoke-test/16301/

[hjyamauchi]

This also reproduces on macos. My reduced test reproduction above is on macos.