Change new List(n) to return fixed length list.

runtime/lib/regexp_patch.dart

 // Copyright (c) 2012, 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.
 
 patch class RegExp {
   /* patch */ factory RegExp(String pattern,
                              {bool multiLine: false,
                               bool caseSensitive: true}) {
     return new _JSSyntaxRegExp(pattern,
                                multiLine: multiLine,
@@ skipping 26 matching lines @@
       return null;
     }
     return str._substringUnchecked(startIndex, endIndex);
   }
 
   String operator [](int groupIdx) {
     return this.group(groupIdx);
   }
 
   List<String> groups(List<int> groupsSpec) {
-    var groupsList = new List<String>.fixedLength(groupsSpec.length);
+    var groupsList = new List<String>(groupsSpec.length);
     for (int i = 0; i < groupsSpec.length; i++) {
       groupsList[i] = group(groupsSpec[i]);
     }
     return groupsList;
   }
 
   int get groupCount => regexp._groupCount;
 
   String get pattern => regexp.pattern;
 
@@ skipping 58 matching lines @@
 
   bool get isMultiLine native "JSSyntaxRegExp_getIsMultiLine";
 
   bool get isCaseSensitive native "JSSyntaxRegExp_getIsCaseSensitive";
 
   int get _groupCount native "JSSyntaxRegExp_getGroupCount";
 
   List _ExecuteMatch(String str, int start_index)
       native "JSSyntaxRegExp_ExecuteMatch";
 }