[es6] enable destructuring rest parameters

test/mjsunit/es6/rest-params.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.
 
 (function testRestIndex() {
   assertEquals(5, (function(...args) { return args.length; })(1,2,3,4,5));
   assertEquals(4, (function(a, ...args) { return args.length; })(1,2,3,4,5));
   assertEquals(3, (function(a, b, ...args) { return args.length; })(1,2,3,4,5));
   assertEquals(2, (function(a, b, c, ...args) {
                       return args.length; })(1,2,3,4,5));
@@ skipping 199 matching lines @@
     function(){ eval("(class{foo(...rest) {'use strict';}});") }, SyntaxError);
 
   assertThrows(
     function(){ eval("function(a, ...rest){'use strict';}") }, SyntaxError);
   assertThrows(
     function(){ eval("(a, ...rest) => {'use strict';}") }, SyntaxError);
   assertThrows(
     function(){ eval("(class{foo(a, ...rest) {'use strict';}});") },
     SyntaxError);
 })();
+
+(function TestRestArrayPattern() {
+  function f(...[a, b, c]) { return a + b + c; }
+  assertEquals(6, f(1, 2, 3));
+  assertEquals("123", f(1, "2", 3));
+  assertEquals(NaN, f(1));
+
+  var f2 = (...[a, b, c]) => a + b + c;
+  assertEquals(6, f2(1, 2, 3));
+  assertEquals("123", f2(1, "2", 3));
+  assertEquals(NaN, f2(1));
+})();
+
+(function TestRestObjectPattern() {
+  function f(...{length, 0: firstName, 1: lastName}) {
+    return `Hello ${lastName}, ${firstName}! Called with ${length} args!`;
+  }
+  assertEquals("Hello Ross, Bob! Called with 4 args!", f("Bob", "Ross", 0, 0));
+
+  var f2 = (...{length, 0: firstName, 1: lastName}) =>
+      `Hello ${lastName}, ${firstName}! Called with ${length} args!`;
+  assertEquals("Hello Ross, Bob! Called with 4 args!", f2("Bob", "Ross", 0, 0));
+})();