Make RegExp's constructor non-const.

utils/apidoc/apidoc.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.
 
 /**
  * This generates the reference documentation for the core libraries that come
  * with dart. It is built on top of dartdoc, which is a general-purpose library
  * for generating docs from any Dart code. This library extends that to include
  * additional information and styling specific to our standard library.
  *
@@ skipping 366 matching lines @@
     // TODO(rnystrom): Hackish. The IO libraries reference this but we don't
     // want it in the docs.
     if (doc.displayName(library) == 'dart:nativewrappers') return;
     super.docLibrary(library);
   }
 
   /** Override definition from parent class to strip out annotation tags. */
   doc.DocComment createDocComment(String text,
                                   [ClassMirror inheritedFrom]) {
     String strippedText =
-        text.replaceAll(const RegExp("@([a-zA-Z]+) ([^;]+)(?:;|\$)"),
+        text.replaceAll(new RegExp("@([a-zA-Z]+) ([^;]+)(?:;|\$)"),
                         '').trim();
     if (strippedText.isEmpty) return null;
     return super.createDocComment(strippedText, inheritedFrom);
   }
 
   doc.DocComment getLibraryComment(LibraryMirror library) {
     if (doc.displayName(library) == HTML_LIBRARY_NAME) {
       return htmldoc.libraryComment;
     }
     return super.getLibraryComment(library);
@@ skipping 182 matching lines @@
    return '''
         <div class="mdn">
         $mdnComment
         <div class="mdn-note"><a href="$mdnUrl">from MDN</a></div>
         </div>
         ''';
   }
 
   String toString() => mdnComment;
 }