Relax --debug-code checks that runtime returns are not the hole

src/ia32/code-stubs-ia32.cc

Index: src/ia32/code-stubs-ia32.cc
diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index e29d834de110d0b616732f725ea8d8b51b84fa73..168bd81a92fdfc0e67e002a74e128a825b5be671 100644
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -5038,12 +5038,16 @@ void CEntryStub::GenerateCore(MacroAssembler* masm,
     __ dec(Operand::StaticVariable(scope_depth));
   }
 
-  // Make sure we're not trying to return 'the hole' from the runtime
-  // call as this may lead to crashes in the IC code later.
+  // Most runtime functions should not return 'the hole'.  Allowing it to escape
+  // may lead to crashes in the IC code later.
   if (FLAG_debug_code) {
     Label okay;
     __ cmp(eax, masm->isolate()->factory()->the_hole_value());
     __ j(not_equal, &okay, Label::kNear);
+    // However, it is expected that SuspendJSGeneratorObject returns the hole.

[Michael Starzinger, 2013/04/25 10:39:57]

I am fine with landing this white-listing for now to make tests pass. But can we
add a TODO here to use another sentinel (e.g. a Harmony symbol) instead? This
has really low priority, it would just be "nice to have".

+    __ cmp(ebx, Immediate(ExternalReference(
+        Runtime::kSuspendJSGeneratorObject, masm->isolate())));
+    __ j(equal, &okay, Label::kNear);
     __ int3();
     __ bind(&okay);
   }