[runtime] PreventExtensionsWithTransition: before adding the new

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index ba593dcbe8274bd1926955d0704bff5c59376a80..5660b27a9505d57c92c5f180c23fe0931649fe48 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2491,6 +2491,9 @@ 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);