[IRGen] Rewrite dead method test in StdlibUnittest

StdlibUnitest is the preferred system for testing that a certain piece
of code crashes. It's also the only way to get this test to pass when
run on an Android host device, since otherwise the device test runner
exits before confirming the output via FileCheck.

Author: modocache

test/IRGen/Inputs/report_dead_method_call/main.swift

@@ -1,4 +1,8 @@
+// The StdlibUnittest test suite is placed here because it contains
+// expressions that are only allowed at the top level in files named
+// "main.swift".
 
+import StdlibUnittest
 
 @inline(never)
 func testProto(_ c: Container) {
@@ -27,16 +31,22 @@ func testPublicClass(_ c: PublicBase) {
 	c.ghi()
 }
 
-switch Process.argc {
-case 1:
-	callClass()
+let ReportDeadMethodCallTestSuite = TestSuite("ReportDeadMethodCall")
 
-case 2:
-	callProto()
+ReportDeadMethodCallTestSuite.test("Call class") {
+  expectCrashLater()
+  callClass()
+}
 
-case 3:
-	callPublicClass()
+ReportDeadMethodCallTestSuite.test("Call proto") {
+  expectCrashLater()
+  callProto()
+}
 
-default:
-	break
+ReportDeadMethodCallTestSuite.test("Call public class") {
+  expectCrashLater()
+  callPublicClass()
 }
+
+runAllTests()
+

test/IRGen/report_dead_method_call.swift

@@ -1,15 +1,15 @@
-// RUN: rm -rf %t && mkdir -p %t
-// RUN: %target-build-swift %S/Inputs/report_dead_method_call/main.swift %s -O -Xfrontend -disable-access-control -o %t/a.out
-// RUN: %target-run %t/a.out 2> %t/err1.log; FileCheck %s < %t/err1.log
-// RUN: %target-run %t/a.out p1 2> %t/err2.log; FileCheck %s < %t/err2.log
-// RUN: %target-run %t/a.out p1 p2 2> %t/err3.log; FileCheck %s < %t/err3.log
-// REQUIRES: executable_test
-
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
 
-// The -disable-access-control option let us "call" methods, which are removed
-// by dead method elimination.
+// We compile with -O (optimizations) and -disable-access-control (which
+// allows use to "call" methods that are removed by dead code elimination).
+// RUN: %target-build-swift %S/Inputs/report_dead_method_call/main.swift %s -O -Xfrontend -disable-access-control -o %t/report_dead_method_call
 
-// CHECK: fatal error: call of deleted method
+// The private, unused methods are optimized away. The test calls these
+// methods anyway (since it has overridden the access control), so we
+// expect them to produce "fatal error: call of deleted method" when run.
+// RUN: %target-run %t/report_dead_method_call
+// REQUIRES: executable_test
 
 private protocol PrivateProto {
 	func abc()