fix list_test for strong mode, and fix DDC List constructors

pkg/dev_compiler/tool/input_sdk/private/ddc_runtime/utils.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 part of dart._runtime;
 
 /// This library defines a set of general javascript utilities for us
 /// by the Dart runtime.
 // TODO(ochafik): Rewrite some of these in Dart when possible.
 
+/// The JavaScript undefined constant.
+/// 
+/// This is initialized by DDC to JS void 0.
+const undefined = null;
+
 defineProperty(obj, name, desc) =>
     JS('', 'Object.defineProperty(#, #, #)', obj, name, desc);
 
 defineValue(obj, name, value) {
   defineProperty(obj, name,
       JS('', '{ value: #, configurable: true, writable: true }', value));
   return value;
 }
 
 void defineGetter(obj, name, getter) {
@@ skipping 101 matching lines @@
 }
 
 @JSExportName('export')
 exportProperty(to, from, name) => copyProperty(to, from, name);
 
 /// Copy properties from source to destination object.
 /// This operation is commonly called `mixin` in JS.
 copyProperties(to, from) {
   return copyTheseProperties(to, from, getOwnNamesAndSymbols(from));
 }