Add Link.copyWithout.

dart/pkg/compiler/lib/src/util/link.dart

 // 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.
 
 part of dart2js.util;
 
 class Link<T> {
   T get head => throw new StateError("no elements");
   Link<T> get tail => null;
 
@@ skipping 109 matching lines @@
 
   /// Returns true if f returns true for all elements of this list.
   ///
   /// Returns true for the empty list.
   bool every(bool f(T)) {
     for (Link<T> link = this; !link.isEmpty; link = link.tail){
       if (!f(link.head)) return false;
     }
     return true;
   }
+
+  Link copyWithout(e) => this;
 }
 
 abstract class LinkBuilder<T> {
   factory LinkBuilder() = LinkBuilderImplementation;
 
   /**
    * Prepends all elements added to the builder to [tail]. The resulting list is
    * returned and the builder is cleared.
    */
   Link<T> toLink([Link<T> tail = const Link()]);
 
   List<T> toList();
 
   void addLast(T t);
 
   final int length;
   final bool isEmpty;
 }