Change RegExp constructor to insist on proper named optional parameters.

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.
 
 class _JSRegExpMatch implements Match {
   _JSRegExpMatch(this.regexp, this.str, this._match);
 
   int start() {
     return _start(0);
   }
@@ skipping 44 matching lines @@
   final RegExp regexp;
   final String str;
   final List<int> _match;
   static const int MATCH_PAIR = 2;
 }
 
 
 patch class JSSyntaxRegExp {
   /* patch */ const factory JSSyntaxRegExp(
       String pattern,
-      [bool multiLine = false,
-       bool ignoreCase = false]) native "JSSyntaxRegExp_factory";
+      {bool multiLine: false,
+       bool ignoreCase: false}) native "JSSyntaxRegExp_factory";
 
   /* patch */ Match firstMatch(String str) {
     List match = _ExecuteMatch(str, 0);
     if (match === null) {
       return null;
     }
     return new _JSRegExpMatch(this, str, match);
   }
 
   /* patch */ Iterable<Match> allMatches(String str) {
@@ skipping 35 matching lines @@
 
   /* patch */ bool get multiLine native "JSSyntaxRegExp_multiLine";
 
   /* patch */ bool get ignoreCase native "JSSyntaxRegExp_ignoreCase";
 
   int get _groupCount native "JSSyntaxRegExp_getGroupCount";
 
   List _ExecuteMatch(String str, int start_index)
       native "JSSyntaxRegExp_ExecuteMatch";
 }