Ensure supertypes are loaded safely.

dart/lib/compiler/implementation/ssa/closure.dart

Index: dart/lib/compiler/implementation/ssa/closure.dart
diff --git a/dart/lib/compiler/implementation/ssa/closure.dart b/dart/lib/compiler/implementation/ssa/closure.dart
index f6f0e3da4b48afc2d79568715998960f1d10fbca..62858e929a7c50342828361605e3bb88f1a69a72 100644
--- a/dart/lib/compiler/implementation/ssa/closure.dart
+++ b/dart/lib/compiler/implementation/ssa/closure.dart
@@ -22,9 +22,13 @@ class ClosureClassElement extends ClassElement {
               // is unique, but also emit closure classes after all other
               // classes (since the emitter sorts classes by their id).
               compiler.getNextFreeClassId()) {
-    isResolved = true;
+    supertypeLoadState = ClassElement.STATE_STARTED;
+    supertypeLoadState = ClassElement.STATE_DONE;

[Lasse Reichstein Nielsen, 2012/08/13 13:34:48]

Wut? This needs a comment!

[ahe, 2012/08/13 15:14:01]

You're right, I actually kept saying to myself that I needed to add a comment
here, but forgot.

Done.

+    resolutionState = ClassElement.STATE_STARTED;
+    resolutionState = ClassElement.STATE_DONE;
     compiler.closureClass.ensureResolved(compiler);
     supertype = compiler.closureClass.computeType(compiler);
+    interfaces = const EmptyLink<Type>();
   }
   bool isClosure() => true;
 }