[debugger] break at each initialization in a multiple var declaration.

test/mjsunit/debug-stepin-accessor-ic.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: --expose-debug-as debug
 
 function get() {
   return 3;                       // Break
 }                                 // Break
 
@@ skipping 27 matching lines @@
   }
 }
 
 var Debug = debug.Debug;
 Debug.setListener(listener);
 
 debugger;                         // Break
 f();                              // Break
 
 Debug.setListener(null);          // Break
-assertEquals(86, break_count);
+assertEquals(87, break_count);
 assertNull(exception);