[keys] support shadowing keys in the KeyAccumulator

src/elements.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/elements.h"
 
 #include "src/arguments.h"
 #include "src/conversions.h"
 #include "src/factory.h"
 #include "src/isolate-inl.h"
@@ skipping 1305 matching lines @@
     if (keys->filter() & SKIP_STRINGS) return;
     Isolate* isolate = keys->isolate();
     Handle<SeededNumberDictionary> dictionary =
         Handle<SeededNumberDictionary>::cast(backing_store);
     int capacity = dictionary->Capacity();
     Handle<FixedArray> elements = isolate->factory()->NewFixedArray(
         GetMaxNumberOfEntries(*object, *backing_store));
     int insertion_index = 0;
     PropertyFilter filter = keys->filter();
     for (int i = 0; i < capacity; i++) {
-      uint32_t key = GetKeyForEntryImpl(isolate, dictionary, i, filter);
-      if (key == kMaxUInt32) continue;
-      Handle<Object> key_handle = isolate->factory()->NewNumberFromUint(key);
-      elements->set(insertion_index, *key_handle);
+      Object* raw_key = dictionary->KeyAt(i);
+      if (!dictionary->IsKey(isolate, raw_key)) continue;
+      uint32_t key = FilterKey(dictionary, i, raw_key, filter);
+      if (key == kMaxUInt32) {
+        keys->AddShadowKey(raw_key);
+        continue;
+      }
+      elements->set(insertion_index, raw_key);
       insertion_index++;
     }
     SortIndices(elements, insertion_index);
     for (int i = 0; i < insertion_index; i++) {
       keys->AddKey(elements->get(i));
     }
   }
 
   static Handle<FixedArray> DirectCollectElementIndicesImpl(
       Isolate* isolate, Handle<JSObject> object,
@@ skipping 1686 matching lines @@
     insertion_index += len;
   }
 
   DCHECK_EQ(insertion_index, result_len);
   return result_array;
 }
 
 ElementsAccessor** ElementsAccessor::elements_accessors_ = NULL;
 }  // namespace internal
 }  // namespace v8