[RGT] Don't use EXPECT* macros in a test subprcess that exits by signalling.

[probinson]

Summary

Found by the Rotten Green Tests project.

[aganea]

LGTM, thanks Paul!

llvm/unittests/Support/CrashRecoveryTest.cpp

 // Just a reachable symbol to ease resolving of the executable's path.
 static cl::opt<std::string> CrashTestStringArg1("crash-test-string-arg1");
 
 TEST(CrashRecoveryTest, UnixCRCReturnCode) {
   using namespace llvm::sys;
   if (getenv("LLVM_CRC_UNIXCRCRETURNCODE")) {
     llvm::CrashRecoveryContext::Enable();
     CrashRecoveryContext CRC;
-    EXPECT_FALSE(CRC.RunSafely(abort));
-    EXPECT_EQ(CRC.RetCode, 128 + SIGABRT);
+    // This path runs in a subprocess that exits by signalling, so don't use
+    // the googletest macros to verify things as they won't report properly.
+    if (CRC.RunSafely(abort))
+      llvm_unreachable("RunSafely returned true!");
+    if (CRC.RetCode != 128 + SIGABRT)
+      llvm_unreachable("Unexpected RetCode!");
     // re-throw signal
     llvm::sys::unregisterHandlers();
     raise(CRC.RetCode - 128);
     llvm_unreachable("Should have exited already!");
   }
 
   std::string Executable =
       sys::fs::getMainExecutable(TestMainArgv0, &CrashTestStringArg1);