Fix non-standard element handling

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 50772bafc201ff56afd53d3eeae033153f5d4173..fa4d66903ca8d6fbeabfc699d6a8a7ebbcabcf0f 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2102,6 +2102,9 @@ class JSObject: public JSReceiver {
   static Handle<SeededNumberDictionary> NormalizeElements(
       Handle<JSObject> object);
 
+  static void RequireSlowElements(Handle<JSObject> object,
+                                  Handle<SeededNumberDictionary> dictionary);
+
   // Transform slow named properties to fast variants.
   static void MigrateSlowToFast(Handle<JSObject> object,
                                 int unused_property_fields, const char* reason);