Don't use `LinkedList` in the core libraries anymore.

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 source,
       {bool multiLine: false, bool caseSensitive: true}) {
     _RegExpHashKey key = new _RegExpHashKey(source, multiLine, caseSensitive);
     _RegExpHashValue value = _cache[key];
 
     if (value == null) {
       if (_cache.length > _MAX_CACHE_SIZE) {
         _RegExpHashKey lastKey = _recentlyUsed.last;
-        lastKey.unlink();
+        _recentlyUsed.remove(lastKey);
         _cache.remove(lastKey);
       }
 
       value = new _RegExpHashValue(
           new _RegExp(source,
               multiLine: multiLine, caseSensitive: caseSensitive),
           key);
       _cache[key] = value;
     } else {
       value.key.unlink();
@@ skipping 12 matching lines @@
   // elements using an LRU eviction strategy.
   // TODO(zerny): Do not impose a fixed limit on the number of cached objects.
   // Other possibilities could be limiting by the size of the regexp objects,
   // or imposing a lower time bound for the most recent use under which a regexp
   // may not be removed from the cache.
   // TODO(zerny): Use self-sizing cache similar to _AccessorCache in
   // mirrors_impl.dart.
   static const int _MAX_CACHE_SIZE = 256;
   static final Map<_RegExpHashKey, _RegExpHashValue> _cache =
       new HashMap<_RegExpHashKey, _RegExpHashValue>();
-  static final LinkedList<_RegExpHashKey> _recentlyUsed =
-      new LinkedList<_RegExpHashKey>();
+  static final internal.LinkedList<_RegExpHashKey> _recentlyUsed =
+      new internal.LinkedList<_RegExpHashKey>();
 }
 
 // Represents both a key in the regular expression cache as well as its
 // corresponding entry in the LRU list.
-class _RegExpHashKey extends LinkedListEntry<_RegExpHashKey> {
+class _RegExpHashKey extends internal.LinkedListEntry<_RegExpHashKey> {
   final String pattern;
   final bool multiLine;
   final bool caseSensitive;
 
   _RegExpHashKey(this.pattern, this.multiLine, this.caseSensitive);
 
   int get hashCode => pattern.hashCode;
   bool operator ==(_RegExpHashKey that) {
     return (this.pattern == that.pattern) &&
         (this.multiLine == that.multiLine) &&
@@ skipping 199 matching lines @@
           _nextIndex++;
         }
         return true;
       }
     }
     _current = null;
     _re = null;
     return false;
   }
 }