[es6] Remove harmony-object-literal flag

test/mjsunit/es6/method-name-eval-arguments.js

 // Copyright 2015 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.
 
-// Flags: --harmony-object-literals
-
 (function TestSloppyMode() {
   var o = {
     eval() {
       return 1;
     },
     arguments() {
       return 2;
     },
   };
 
   assertEquals(1, o.eval());
   assertEquals(2, o.arguments());
 })();
 
 (function TestStrictMode() {
   'use strict';
 
   var o = {
     eval() {
       return 1;
     },
     arguments() {
       return 2;
     },
   };
 
   assertEquals(1, o.eval());
   assertEquals(2, o.arguments());
 })();