Remove always-true --harmony-restrictive-declarations flag

test/mjsunit/regress/regress-542099.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: --no-harmony-restrictive-declarations
-
-// Previously, this caused a CHECK fail in debug mode
-// https://code.google.com/p/chromium/issues/detail?id=542099
-
-var foo = {};
-var bar = foo;
-for (foo.x in {a: 1}) function foo() { return foo; }
-assertEquals("object", typeof bar);
-assertEquals("a", bar.x);
-assertEquals("function", typeof foo);
-assertEquals("function", typeof foo());
-assertSame(foo, foo());
-assertEquals(undefined, foo.x);