Remove runtime flags for Proxy and Reflect

test/mjsunit/es6/proxies-prototype-target-stackoverflow.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
-
 // Test that traps that involve walking the target object's prototype chain
 // don't overflow the stack when the original proxy is on that chain.
 
 (function TestGetPrototype() {
   var p = new Proxy({}, {});
   p.__proto__ = p;
   try { return p.__proto__; } catch(e) { assertInstanceof(e, RangeError); }
 })();
 
 (function TestSetPrototype() {
@@ skipping 71 matching lines @@
   var p = new Proxy(function() {}, {});
   p.__proto__ = p;
   return p();
 })();
 
 (function TestConstruct() {
   var p = new Proxy(function() { this.foo = 1; }, {});
   p.__proto__ = p;
   return new p();
 })();