Remove most superfluous getter arguments from dart2js.

dart/lib/compiler/implementation/util/link_implementation.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.
 
 class LinkIterator<T> implements Iterator<T> {
   Link<T> current;
   LinkIterator(Link<T> this.current);
   bool hasNext() => !current.isEmpty();
   T next() {
     T result = current.head;
@@ skipping 23 matching lines @@
     }
     Link link = new Link<T>(list.last());
     for (int i = list.length - 1; i > 0; i--) {
       link = link.prepend(list[i - 1]);
     }
     return link;
   }
 }
 
 class LinkTail<T> implements EmptyLink<T> {
-  T get head() => null;
-  Link<T> get tail() => null;
+  T get head => null;
+  Link<T> get tail => null;
 
   const LinkTail();
 
   Link<T> prepend(T element) {
     // TODO(ahe): Use new Link<T>, but this cost 8% performance on VM.
     return new LinkEntry<T>(element, this);
   }
 
   Iterator<T> iterator() => new LinkIterator<T>(this);
 
@@ skipping 100 matching lines @@
     length++;
     LinkEntry<T> entry = new LinkEntry<T>(t, null);
     if (head === null) {
       head = entry;
     } else {
       lastLink.tail = entry;
     }
     lastLink = entry;
   }
 }