Enable ES6 generators

test/mjsunit/es6/regress/regress-3280.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-generators --expose-debug-as debug
+// Flags: --expose-debug-as debug
 
 var Debug = debug.Debug;
 
 var listener_called;
 
 function listener(event, exec_state, event_data, data) {
   if (event == Debug.DebugEvent.Break) {
     listener_called = true;
     exec_state.frame().allScopes();
   }
 }
 
 Debug.setListener(listener);
 
 function *generator_local_2(a) {
   debugger;
 }
 generator_local_2(1).next();
 
 assertTrue(listener_called, "listener not called");