Change the check for builtin functions to not be based on identity,...

src/objects-inl.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2323 matching lines @@
   // TODO(1242782): Create a code kind for uncompiled code.
   return code()->kind() != Code::STUB;
 }
 
 
 bool JSFunction::IsBoilerplate() {
   return map() == Heap::boilerplate_function_map();
 }
 
 
+bool JSFunction::IsBuiltin() {
+  return context()->global()->IsJSBuiltinsObject();
+}
+
+
 bool JSObject::IsLoaded() {
   return !map()->needs_loading();
 }
 
 
 Code* JSFunction::code() {
   return shared()->code();
 }
 
 
@@ skipping 488 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_