Remove --harmony-scoping flag.

test/mjsunit/es6/regress/regress-2858.js

 // Copyright 2014 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-scoping
 "use strict";
 
 function f() {
     var y = 1;
     var q1;
     var q;
     var z = new Error();
     try {
         throw z;
     } catch (y) {
       assertTrue(z === y);
       q1 = function() { return y; }
       var y = 15;
       q = function() { return y; }
       assertSame(15, y);
     }
     assertSame(1, y);
     assertSame(15, q1());
     assertSame(15, q());
 }
 
 f();