Version 4.9.385.15 (cherry-pick)

test/mjsunit/harmony/regress/regress-crbug-571149.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.
+
+
+(function(a = 0){
+  var x;  // allocated in a var block, due to use of default parameter
+  (function() { return !x })();
+})();
+
+(function({a}){
+  var x;  // allocated in a var block, due to use of parameter destructuring
+  (function() { return !x })();
+})({});
+
+(function(...a){
+  var x;  // allocated in a var block, due to use of rest parameter
+  (function() { return !x })();
+})();