[debugger] Further stepping support in test wrapper

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
-
-function set(x) {
-  this.x = x;                     // Break
-}                                 // Break
-
-var o = {};
-Object.defineProperty(o, "get", { get : get });
-Object.defineProperty(o, "set", { set : set });
-
-function f() {
-  for (var i = 0; i < 10; i++) {  // Break
-    o.get;                        // Break
-    o.set = 1;                    // Break
-  }
-}                                 // Break
-
-var break_count = 0;
-var exception = null;
-
-function listener(event, exec_state, event_data, data) {
-  if (event != Debug.DebugEvent.Break) return;
-  try {
-    var source_line = exec_state.frame(0).sourceLineText();
-    assertTrue(source_line.indexOf("// Break") > 0);
-    exec_state.prepareStep(Debug.StepAction.StepIn);
-    break_count++;
-  } catch (e) {
-    exception = e;
-  }
-}
-
-var Debug = debug.Debug;
-Debug.setListener(listener);
-
-debugger;                         // Break
-f();                              // Break
-
-Debug.setListener(null);          // Break
-assertEquals(86, break_count);
-assertNull(exception);