Add "last" setter to List.

runtime/lib/array.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.
 
 
 // TODO(srdjan): Use shared array implementation.
 class _List<E> implements List<E> {
   static final int _classId = (new _List(0))._cid;
 
   factory _List(length) native "List_allocate";
@@ skipping 225 matching lines @@
   E get first {
     if (length > 0) return this[0];
     throw IterableElementError.noElement();
   }
 
   E get last {
     if (length > 0) return this[length - 1];
     throw IterableElementError.noElement();
   }
 
+  void set last(E value) {
+    if (length == 0) throw IterableElementError.noElement();
+    this[length - 1] = value;
+  }
+
   E get single {
     if (length == 1) return this[0];
     if (length == 0) throw IterableElementError.noElement();
     throw IterableElementError.tooMany();
   }
 
   List<E> toList({ bool growable: true}) {
     return new List<E>.from(this, growable: growable);
   }
 
@@ skipping 24 matching lines @@
 
   factory _ImmutableList._from(List from, int offset, int length)
       native "ImmutableList_from";
 
   E operator [](int index) native "List_getIndexed";
 
   void operator []=(int index, E value) {
     throw UnmodifiableListError.change();
   }
 
+  void set last(E value) {
+    throw UnmodifiableListError.change();
+  }
+
   int get length native "List_getLength";
 
   void insert(int index, E element) {
     throw UnmodifiableListError.add();
   }
 
   void insertAll(int index, Iterable<E> iterable) {
     throw UnmodifiableListError.add();
   }
 
@@ skipping 230 matching lines @@
     }
     _position = _length;
     _current = null;
     return false;
   }
 
   E get current {
     return _current;
   }
 }