Several mjsunit cleanups

test/mjsunit/harmony/debug-stepin-default-parameters.js

-// Copyright 2015 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 --harmony-default-parameters
-
-Debug = debug.Debug
-
-var exception = null;
-var log = [];
-
-function listener(event, exec_state, event_data, data) {
-  if (event != Debug.DebugEvent.Break) return;
-  try {
-    print(event_data.sourceLineText());
-    var entry = "";
-    for (var i = 0; i < exec_state.frameCount(); i++) {
-      entry += exec_state.frame(i).sourceLineText().substr(-1);
-      entry += exec_state.frame(i).sourceColumn();
-    }
-    log.push(entry);
-    exec_state.prepareStep(Debug.StepAction.StepIn);
-  } catch (e) {
-    exception = e;
-  }
-};
-
-function default_arg(x) {
-  return "default";                 // d
-}                                   // e
-
-function f(arg0 = default_arg()) {  // f
-  return arg0;                      // g
-}                                   // h
-
-
-Debug.setListener(listener);
-debugger;                           // a
-var result = f();                   // b
-Debug.setListener(null);            // c
-
-assertNull(exception);
-assertEquals("default", result);
-
-assertEquals(["a0","b13","f18b13","d2f18b13","e0f18b13","g2b13","h0b13","c0"],
-             log);