[es6] Remove harmony-classes flag

test/mjsunit/es6/regress/regress-3750.js

Index: test/mjsunit/es6/regress/regress-3750.js
diff --git a/test/mjsunit/harmony/regress/regress-3750.js b/test/mjsunit/es6/regress/regress-3750.js
similarity index 88%
rename from test/mjsunit/harmony/regress/regress-3750.js
rename to test/mjsunit/es6/regress/regress-3750.js
index d1f21f9bd39a088f51b25d53ad32ef98d40d0c1e..a425def2b751c90d08e8df6352ba0b6a9e3a70fa 100644
--- a/test/mjsunit/harmony/regress/regress-3750.js
+++ b/test/mjsunit/es6/regress/regress-3750.js
@@ -1,8 +1,7 @@
 // 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-classes
+
 'use strict';
 class Example { }
 Object.observe(Example.prototype, function(){});