[regexp] ship unicode regexps.

test/mjsunit/es6/no-unicode-regexp-flag.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.
 
 // Before Unicode RegExps are shipped, we shouldn't have the 'unicode'
 // property on RegExp.prototype, or read it from 'flags'.
 // mjsunit/es6/regexp-flags tests that the property is there when the
 // flag is on.
 
-// Flags: --harmony-regexp
+// Flags: --harmony-regexps --no-harmony-unicode-regexps
 
 'use strict';
 
 assertFalse(RegExp.prototype.hasOwnProperty('unicode'));
 
 // If we were going to be really strict, we could have a test like this,
 // with the assertTrue replaced by assertFalse, since flags shouldn't
 // Get the 'unicode' property. However, it is probably OK to omit this
 // detailed fix.
 var x = /a/;
 var y = false;
 Object.defineProperty(x, 'unicode', { get() { y = true; } });
 assertEquals("", x.flags);
 assertTrue(y);