Make debugger step into bound callbacks passed to Array.forEach.

src/harmony-typedarray.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.
 
 "use strict";
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Array = global.Array;
 
@@ skipping 31 matching lines @@
     receiver = %_Arguments(1);
   }
 
   var needs_wrapper = false;
   if (IS_NULL_OR_UNDEFINED(receiver)) {
     receiver = %GetDefaultReceiver(f) || receiver;
   } else {
     needs_wrapper = SHOULD_CREATE_WRAPPER(f, receiver);
   }
 
-  var stepping = DEBUG_IS_ACTIVE && %DebugCallbackSupportsStepping(f);
+  var stepping = DEBUG_IS_STEPPING();
   for (var i = 0; i < length; i++) {
     var element = this[i];
     // Prepare break slots for debugger step in.
     if (stepping) %DebugPrepareStepInIfStepping(f);
     var new_receiver = needs_wrapper ? ToObject(receiver) : receiver;
     %_CallFunction(new_receiver, TO_OBJECT_INLINE(element), i, this, f);
   }
 }
 
 // ES6 draft 08-24-14, section 22.2.2.2
@@ skipping 23 matching lines @@
   // Set up non-enumerable functions on the prototype object.
   InstallFunctions(global.NAME.prototype, DONT_ENUM, $Array(
     "forEach", NAMEForEach
   ));
 endmacro
 
   TYPED_ARRAYS(EXTEND_TYPED_ARRAY)
 }
 
 HarmonyTypedArrayExtendPrototypes();