[Arguments] Support getters and setters on non-strict arguments objects.

src/runtime.cc

 // Copyright 2010 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 861 matching lines @@
       }
 
       case JSObject::DICTIONARY_ELEMENT: {
         Handle<JSObject> holder = obj;
         if (obj->IsJSGlobalProxy()) {
           Object* proto = obj->GetPrototype();
           if (proto->IsNull()) return heap->undefined_value();
           ASSERT(proto->IsJSGlobalObject());
           holder = Handle<JSObject>(JSObject::cast(proto));
         }
-        NumberDictionary* dictionary = holder->element_dictionary();
+        FixedArray* elements = FixedArray::cast(holder->elements());
+        NumberDictionary* dictionary = NULL;
+        if (elements->map() == heap->non_strict_arguments_elements_map()) {
+          dictionary = NumberDictionary::cast(elements->get(1));
+        } else {
+          dictionary = NumberDictionary::cast(elements);
+        }
         int entry = dictionary->FindEntry(index);
         ASSERT(entry != NumberDictionary::kNotFound);
         PropertyDetails details = dictionary->DetailsAt(entry);
         switch (details.type()) {
           case CALLBACKS: {
             // This is an accessor property with getter and/or setter.
             FixedArray* callbacks =
                 FixedArray::cast(dictionary->ValueAt(entry));
             elms->set(IS_ACCESSOR_INDEX, heap->true_value());
             if (CheckElementAccess(*obj, index, v8::ACCESS_GET)) {
@@ skipping 11404 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     COUNTERS->gc_last_resort_from_js()->Increment();
     HEAP->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal