Remove addLast from List.

tools/dom/templates/immutable_list_mixin.darttemplate

   // -- start List<$E> mixins.
   // $E is the element type.
 
   // From Iterable<$E>:
 
   Iterator<$E> get iterator {
     // Note: NodeLists are not fixed size. And most probably length shouldn't
     // be cached in both iterator _and_ forEach method. For now caching it
     // for consistency.
     return new FixedSizeListIterator<$E>(this);
@@ skipping 65 matching lines @@
   $E elementAt(int index) {
     return this[index];
   }
 
   // From Collection<$E>:
 
   void add($E value) {
     throw new UnsupportedError("Cannot add to immutable List.");
   }
 
-  void addLast($E value) {
-    throw new UnsupportedError("Cannot add to immutable List.");
-  }
-
   void addAll(Iterable<$E> iterable) {
     throw new UnsupportedError("Cannot add to immutable List.");
   }
 
   // From List<$E>:
 $if DEFINE_LENGTH_SETTER
   void set length(int value) {
     throw new UnsupportedError("Cannot resize immutable List.");
   }
 $endif
@@ skipping 93 matching lines @@
     return Lists.getRange(this, start, end, <$E>[]);
   }
 
   List<$E> getRange(int start, int rangeLength) =>
       sublist(start, start + rangeLength);
 
   Map<int, $E> asMap() =>
     IterableMixinWorkaround.asMapList(this);
 
   // -- end List<$E> mixins.