move-only: support deinits which get the self argument as indirect argument

This happens for address-only move-only types.

(cherry picked from commit c4ae7fe)

Author: eeckstein

lib/SIL/IR/SILFunctionType.cpp

@@ -2385,7 +2385,7 @@ struct DeallocatorConventions : Conventions {
 
   ParameterConvention
   getIndirectSelfParameter(const AbstractionPattern &type) const override {
-    llvm_unreachable("Deallocators do not have indirect self parameters");
+    return ParameterConvention::Indirect_In;
   }
 
   static bool classof(const Conventions *C) {

lib/SIL/Verifier/SILVerifier.cpp

@@ -674,6 +674,7 @@ struct ImmutableAddressUseVerifier {
       case SILInstructionKind::IndexAddrInst:
       case SILInstructionKind::TailAddrInst:
       case SILInstructionKind::IndexRawPointerInst:
+      case SILInstructionKind::MarkMustCheckInst:
         // Add these to our worklist.
         for (auto result : inst->getResults()) {
           llvm::copy(result->getUses(), std::back_inserter(worklist));

lib/SILGen/SILGenProlog.cpp

@@ -40,7 +40,7 @@ static void diagnose(ASTContext &Context, SourceLoc loc, Diag<T...> diag,
 
 SILValue SILGenFunction::emitSelfDeclForDestructor(VarDecl *selfDecl) {
   // Emit the implicit 'self' argument.
-  SILType selfType = getLoweredLoadableType(selfDecl->getType());
+  SILType selfType = getLoweredType(selfDecl->getType());
   SILValue selfValue = F.begin()->createFunctionArgument(selfType, selfDecl);
 
   // If we have a move only type, then mark it with mark_must_check so we can't