Remove runtime flags for Proxy and Reflect

test/mjsunit/es6/classes-subclass-builtins.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: --allow-natives-syntax --harmony-reflect --harmony-regexp-subclass
+// Flags: --allow-natives-syntax --harmony-regexp-subclass
 // Flags: --expose-gc
 
 "use strict";
 
 
 function checkPrototypeChain(object, constructors) {
   var proto = object.__proto__;
   for (var i = 0; i < constructors.length; i++) {
     assertEquals(constructors[i].prototype, proto);
     assertEquals(constructors[i], proto.constructor);
@@ skipping 900 matching lines @@
 
   Object.defineProperty(pattern, Symbol.match, {
     get() { log.push("match"); f.prototype = p2; return false; }});
 
   var o = Reflect.construct(RegExp, [pattern], f);
   assertEquals(["match", "tostring"], log);
   assertEquals(/biep/, o);
   assertTrue(o.__proto__ === p2);
   assertTrue(f.prototype === p3);
 })();