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

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
 
-// Test that hidden scopes are correctly walked in the scope chain.
-
-var Debug = debug.Debug;
-var exception = null;
-var delegate = null;
-var done = false;
-
 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 ],
-                 exec_state.frame(0).allScopes().map(s => s.scopeType()));
-    done = true;
+                 all_scopes.map(scope => scope.scopeType()));
   } catch (e) {
     exception = e;
   }
 }
 
-Debug.setListener(listener);
+debug.Debug.setListener(listener);
 
-for(let a = 0; a < 3; a++) {
+(function(arg, ...rest) {
+  var one = 1;
+  function inner() {
+    one;
+    arg;
+  }
   debugger;
-  eval();  // Force context-allocation of everything.
-}
-
-Debug.setListener(null);
-assertNull(exception);
-assertTrue(done);
+})();