[debugger] add test case for scope materialization and rest params.

R=jgruber@chromium.org
BUG=v8:4703

Review-Url: https://codereview.chromium.org/2088703002
Cr-Commit-Position: refs/heads/master@{#37169}

test/mjsunit/regress/regress-4703.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
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Break) return;
+  try {
+    var all_scopes = exec_state.frame().allScopes();
+    assertEquals([ debug.ScopeType.Block,
+                   debug.ScopeType.Local,
+                   debug.ScopeType.Script,
+                   debug.ScopeType.Global ],
+                 all_scopes.map(scope => scope.scopeType()));
+  } catch (e) {
+    exception = e;
+  }
+}
+
+debug.Debug.setListener(listener);
+
+(function(arg, ...rest) {
+  var one = 1;
+  function inner() {
+    one;
+    arg;
+  }
+  debugger;
+})();