Added dictionary that can use objects as keys.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index eb537c75a05b301c7a6aedfc5b31243c1259e89d..6c81f0a89f11c72450f7a746821d1f1bd5949d30 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -4302,6 +4302,32 @@ MaybeObject* StringDictionaryShape::AsObject(String* key) {
 }
 
 
+bool ObjectDictionaryShape::IsMatch(JSObject* key, Object* other) {
+  ASSERT(other->IsJSObject());
+  return key == JSObject::cast(other);
+}
+
+
+uint32_t ObjectDictionaryShape::Hash(JSObject* key) {
+  MaybeObject* maybe_hash = key->GetIdentityHash();
+  ASSERT(!maybe_hash->IsFailure());
+  return Smi::cast(maybe_hash->ToObjectUnchecked())->value();
+}
+
+
+uint32_t ObjectDictionaryShape::HashForObject(JSObject* key, Object* other) {
+  ASSERT(other->IsJSObject());
+  MaybeObject* maybe_hash = JSObject::cast(other)->GetIdentityHash();
+  ASSERT(!maybe_hash->IsFailure());
+  return Smi::cast(maybe_hash->ToObjectUnchecked())->value();
+}
+
+
+MaybeObject* ObjectDictionaryShape::AsObject(JSObject* key) {
+  return key;
+}
+
+
 void Map::ClearCodeCache(Heap* heap) {
   // No write barrier is needed since empty_fixed_array is not in new space.
   // Please note this function is used during marking: