Add add and subtract operations to Uint32x4

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 a145ff2eac91a63c9a75cfcc68be798464d1f65b..a85651e63975244203030b8ceeb3297d37af7724 100644
--- a/sdk/lib/typed_data/dart2js/typed_data_dart2js.dart
+++ b/sdk/lib/typed_data/dart2js/typed_data_dart2js.dart
@@ -1396,6 +1396,24 @@ class Uint32x4 {
     return new Uint32x4(_x, _y, _z, _w);
   }
 
+  Uint32x4 operator+(Uint32x4 other) {
+    var r = new Uint32x4(0, 0, 0, 0);
+    r._storage[0] = (_storage[0] + other._storage[0])|0;

[srdjan, 2013/08/19 21:45:23]

Why '| 0'? In JS this creates an uint32 but shouldn't  dart2js emit appropriate
code instead of writing JS like code in Dart? 

[Cutch, 2013/08/19 21:58:25]

Done.

+    r._storage[1] = (_storage[1] + other._storage[1])|0;
+    r._storage[2] = (_storage[2] + other._storage[2])|0;
+    r._storage[3] = (_storage[3] + other._storage[3])|0;
+    return r;
+  }
+
+  Uint32x4 operator-(Uint32x4 other) {
+    var r = new Uint32x4(0, 0, 0, 0);
+    r._storage[0] = (_storage[0] - other._storage[0])|0;
+    r._storage[1] = (_storage[1] - other._storage[1])|0;
+    r._storage[2] = (_storage[2] - other._storage[2])|0;
+    r._storage[3] = (_storage[3] - other._storage[3])|0;
+    return r;
+  }
+
   /// Extract 32-bit mask from x lane.
   int get x => _storage[0];
   /// Extract 32-bit mask from y lane.