Use JavaScript's Array.sort.

dart/lib/compiler/implementation/lib/js_helper.dart

Index: dart/lib/compiler/implementation/lib/js_helper.dart
diff --git a/dart/lib/compiler/implementation/lib/js_helper.dart b/dart/lib/compiler/implementation/lib/js_helper.dart
index 80d93d3d4b016b31f0727a0c8f4f33e1d654d32c..da13b346aa1d231e8d1a6747b389059e5fb17811 100644
--- a/dart/lib/compiler/implementation/lib/js_helper.dart
+++ b/dart/lib/compiler/implementation/lib/js_helper.dart
@@ -1412,3 +1412,19 @@ String getRuntimeTypeString(var object) {
   var typeInfo = JS('Object', r'#.builtin$typeInfo', object);
   return JS('String', r'#.runtimeType', typeInfo);
 }
+
+compareHelperNull(compare, a, b) {
+  if (const NullSentinel() == a) {
+    a = null;
+  }
+  if (const NullSentinel() == b) {
+    b = null;
+  }
+  compare(a, b);

[Lasse Reichstein Nielsen, 2012/10/18 11:54:50]

return result?
(I.e., is this tested? :)

+}
+
+compareHelper(compare, a, b) => compare(a, b);
+
+class NullSentinel {
+  const NullSentinel();
+}