ES6: Add support for Map and Set Iterator

test/cctest/test-api.cc

 // Copyright 2012 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 21411 matching lines @@
   v8::HandleScope scope(isolate);
   Local<ObjectTemplate> templ = ObjectTemplate::New(isolate);
   Local<Object> obj = templ->NewInstance();
   obj->GetIdentityHash();
   obj->DeleteHiddenValue(v8_str("Bug"));
 }
 
 
 THREADED_TEST(Regress2535) {
   i::FLAG_harmony_collections = true;
+  i::FLAG_harmony_symbols = true;
   LocalContext context;
   v8::HandleScope scope(context->GetIsolate());
   Local<Value> set_value = CompileRun("new Set();");
   Local<Object> set_object(Local<Object>::Cast(set_value));
   CHECK_EQ(0, set_object->InternalFieldCount());
   Local<Value> map_value = CompileRun("new Map();");
   Local<Object> map_object(Local<Object>::Cast(map_value));
   CHECK_EQ(0, map_object->InternalFieldCount());
 }
 
@@ skipping 1217 matching lines @@
   Local<Script> script = v8::ScriptCompiler::Compile(
       isolate, &script_source);
   Local<Value> script_name = script->GetUnboundScript()->GetScriptName();
   CHECK(!script_name.IsEmpty());
   CHECK(script_name->IsString());
   String::Utf8Value utf8_name(script_name);
   CHECK_EQ(url, *utf8_name);
   int line_number = script->GetUnboundScript()->GetLineNumber(0);
   CHECK_EQ(13, line_number);
 }