Reintroduced dictionary that can use objects as keys.

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index d73aaf0fca671fed228d4996c5e70872713eee8e..c9984aa92f3d8c7620dbdfe762cbf06817235ed7 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -422,43 +422,18 @@ Handle<Object> PreventExtensions(Handle<JSObject> object) {
 
 
 Handle<Object> GetHiddenProperties(Handle<JSObject> obj,
-                                   bool create_if_needed) {
-  Isolate* isolate = obj->GetIsolate();
-  Object* holder = obj->BypassGlobalProxy();
-  if (holder->IsUndefined()) return isolate->factory()->undefined_value();
-  obj = Handle<JSObject>(JSObject::cast(holder), isolate);
-
-  if (obj->HasFastProperties()) {
-    // If the object has fast properties, check whether the first slot
-    // in the descriptor array matches the hidden symbol. Since the
-    // hidden symbols hash code is zero (and no other string has hash
-    // code zero) it will always occupy the first entry if present.
-    DescriptorArray* descriptors = obj->map()->instance_descriptors();
-    if ((descriptors->number_of_descriptors() > 0) &&
-        (descriptors->GetKey(0) == isolate->heap()->hidden_symbol()) &&
-        descriptors->IsProperty(0)) {
-      ASSERT(descriptors->GetType(0) == FIELD);
-      return Handle<Object>(obj->FastPropertyAt(descriptors->GetFieldIndex(0)),
-                            isolate);
-    }
-  }
+                                   JSObject::HiddenPropertiesFlag flag) {
+  CALL_HEAP_FUNCTION(obj->GetIsolate(),
+                     obj->GetHiddenProperties(flag),
+                     Object);
+}
 
-  // Only attempt to find the hidden properties in the local object and not
-  // in the prototype chain.  Note that HasLocalProperty() can cause a GC in
-  // the general case in the presence of interceptors.
-  if (!obj->HasHiddenPropertiesObject()) {
-    // Hidden properties object not found. Allocate a new hidden properties
-    // object if requested. Otherwise return the undefined value.
-    if (create_if_needed) {
-      Handle<Object> hidden_obj =
-          isolate->factory()->NewJSObject(isolate->object_function());
-      CALL_HEAP_FUNCTION(isolate,
-                         obj->SetHiddenPropertiesObject(*hidden_obj), Object);
-    } else {
-      return isolate->factory()->undefined_value();
-    }
-  }
-  return Handle<Object>(obj->GetHiddenPropertiesObject(), isolate);
+
+int GetIdentityHash(Handle<JSObject> obj) {
+  CALL_AND_RETRY(obj->GetIsolate(),
+                 obj->GetIdentityHash(JSObject::ALLOW_CREATION),
+                 return Smi::cast(__object__)->value(),
+                 return 0);
 }
 
 
@@ -908,6 +883,15 @@ Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object,
 }
 
 
+Handle<ObjectHashTable> PutIntoObjectHashTable(Handle<ObjectHashTable> table,
+                                               Handle<JSObject> key,
+                                               Handle<Object> value) {
+  CALL_HEAP_FUNCTION(table->GetIsolate(),
+                     table->Put(*key, *value),
+                     ObjectHashTable);
+}
+
+
 bool EnsureCompiled(Handle<SharedFunctionInfo> shared,
                     ClearExceptionFlag flag) {
   return shared->is_compiled() || CompileLazyShared(shared, flag);