[runtime] PreventExtensionsWithTransition: before adding the new

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 2ede42a9921d482893f4177c03e612bba0cf842b..e2b94ef55a6689e9c045bac996bd1eec1f87f6d9 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2480,6 +2480,9 @@ class JSObject: public JSReceiver {
   // Check whether this object references another object
   bool ReferencesObject(Object* obj);
 
+  MUST_USE_RESULT static Maybe<bool> TestIntegrityLevel(Handle<JSObject> object,
+                                                        IntegrityLevel lvl);
+
   MUST_USE_RESULT static Maybe<bool> PreventExtensions(
       Handle<JSObject> object, ShouldThrow should_throw);