Don't perform access checks for internally used properties

src/lookup-inl.h

Index: src/lookup-inl.h
diff --git a/src/lookup-inl.h b/src/lookup-inl.h
index ffc02e78783adefdd8216ef09313403f857d6b8b..50f4b0fcc9ddad89849b64fa71183077f8f97480 100644
--- a/src/lookup-inl.h
+++ b/src/lookup-inl.h
@@ -38,7 +38,10 @@ LookupIterator::State LookupIterator::LookupInHolder(Map* map,
   switch (state_) {
     case NOT_FOUND:
       if (map->IsJSProxyMap()) return JSPROXY;
-      if (map->is_access_check_needed()) return ACCESS_CHECK;
+      if (map->is_access_check_needed() &&
+          !isolate_->IsInternallyUsedPropertyName(name_)) {
+        return ACCESS_CHECK;
+      }
     // Fall through.
     case ACCESS_CHECK:
       if (check_interceptor() && map->has_named_interceptor()) {