Add List.reversed to give a reverse fixed-length view of a list.

runtime/lib/array.dart

Index: runtime/lib/array.dart
diff --git a/runtime/lib/array.dart b/runtime/lib/array.dart
index d7fac3ad174401f9778185bcc01bd4080fa78db5..e7c4bee5b9b9f28652adcc711b2e4d5d1dcff822 100644
--- a/runtime/lib/array.dart
+++ b/runtime/lib/array.dart
@@ -154,6 +154,8 @@ class _ObjectArray<E> implements List<E> {
     return this.length == 0;
   }
 
+  List<E> get reversed => new ReversedListView<E>(this, 0, null);
+
   void sort([int compare(E a, E b)]) {
     IterableMixinWorkaround.sortList(this, compare);
   }
@@ -382,6 +384,8 @@ class _ImmutableArray<E> implements List<E> {
     return this.length == 0;
   }
 
+  List<E> get reversed => new ReversedListView<E>(this, 0, null);
+
   void sort([int compare(E a, E b)]) {
     throw new UnsupportedError(
         "Cannot modify an immutable array");