Fix dart2js and dart2dart buildbot breakage

sdk/lib/typed_data/dart2js/typed_data_dart2js.dart

Index: sdk/lib/typed_data/dart2js/typed_data_dart2js.dart
diff --git a/sdk/lib/typed_data/dart2js/typed_data_dart2js.dart b/sdk/lib/typed_data/dart2js/typed_data_dart2js.dart
index ca6e1667e3a4ddabe763e7721ed88ebe3e001c55..0c761ff5fada6cf08d77cb9545de22cb4d3bf27c 100644
--- a/sdk/lib/typed_data/dart2js/typed_data_dart2js.dart
+++ b/sdk/lib/typed_data/dart2js/typed_data_dart2js.dart
@@ -705,8 +705,9 @@ class Float32x4List
 
   factory Float32x4List.fromList(List<Float32x4> list) {
     if (list is Float32x4List) {
+      Float32x4List nativeList = list as Float32x4List;

[ahe, 2013/07/25 17:51:49]

What is the cast for?

[Cutch, 2013/07/25 17:53:53]

It fixes the checked mode failure that was complaining that List does not have a
_storage member.

[ahe, 2013/07/25 18:04:12]

That should be fixed by the assignment. Why the cast?

       return new Float32x4List._externalStorage(
-          new Float32List.fromList(list._storage));
+          new Float32List.fromList(nativeList._storage));
     } else {
       return new Float32x4List._slowFromList(list);
     }