Remove runtime flags for Proxy and Reflect

test/mjsunit/es6/proxies-revocable.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-proxies --harmony-reflect
-
 
 traps = [
     "getPrototypeOf", "setPrototypeOf", "isExtensible", "preventExtensions",
     "getOwnPropertyDescriptor", "has", "get", "set", "deleteProperty",
     "defineProperty", "ownKeys", "apply", "construct"
 ];
 
 var {proxy, revoke} = Proxy.revocable({}, {});
 assertEquals(0, revoke.length);
 
 assertEquals(undefined, revoke());
 for (var trap of traps) {
   assertThrows(() => Reflect[trap](proxy), TypeError);
 }
 
 assertEquals(undefined, revoke());
 for (var trap of traps) {
   assertThrows(() => Reflect[trap](proxy), TypeError);
 }