Added SIMD stubs for dart2js

sdk/lib/html/dart2js/html_dart2js.dart

 /// The Dart HTML library.
 library dart.dom.html;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:_collection-dev';
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:isolate';
 import 'dart:json' as json;
@@ skipping 29523 matching lines @@
 
   static _get(p, m) => JS('var', '#[#]', p, m);
   static _set(p, m, v) => JS('void', '#[#] = #', p, m, v);
 }
 // Copyright (c) 2013, 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.
 
 
 class Platform {
+  /**
+   * Returns true if dart:typed_data types are supported on this
+   * browser.  If false, using these types will generate a runtime
+   * error.
+   */
   static final supportsTypedData = JS('bool', '!!(window.ArrayBuffer)');
+
+  /**
+   * Returns true if SIMD types in dart:typed_data types are supported
+   * on this browser.  If false, using these types will generate a runtime
+   * error.
+   */
+  static final supportsSimd = false;
 }
 // Copyright (c) 2011, 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.
 
 
 // Iterator for arrays with fixed size.
 class FixedSizeListIterator<T> implements Iterator<T> {
   final List<T> _array;
   final int _length;  // Cache array length for faster access.
@@ skipping 37 matching lines @@
       _position = nextPosition;
       return true;
     }
     _current = null;
     _position = _array.length;
     return false;
   }
 
   T get current => _current;
 }