[debug-wrapper] Further extend the debug wrapper

test/debugger/debug/es6/debug-evaluate-receiver-before-super.js

 // Copyright 2016 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: --expose-debug-as debug
 
 // Test that debug-evaluate doesn't crash when this is used before super() call
 // in constructor.
 
 Debug = debug.Debug
 
 var result;
 
 function listener(event, exec_state, event_data, data)
 {
   try {
     if (event == Debug.DebugEvent.Break) {
       result = exec_state.frame(0).evaluate("this.a").value();
     }
   } catch (e) {
     result = e.message;
   }
 }
 
 Debug.setListener(listener);
 
 class A { constructor () { this.a = 239; } }
 class B extends A {
   constructor () {
     debugger;
-    assertEquals("Cannot read property 'a' of undefined", result);
+    assertTrue(result.indexOf("Cannot read property 'a' of undefined") >= 0);
     super();
     debugger;
     assertEquals(239, result);
   }
 }
 new B();
 
 Debug.setListener(null);