Allow infering of return types on runtime helpers. It's only arugments the inferrer does not see.

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/backend.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/js_backend/backend.dart	(revision 26184)
+++ sdk/lib/_internal/compiler/implementation/js_backend/backend.dart	(working copy)
@@ -903,13 +903,18 @@
 
   void registerThrowNoSuchMethod(TreeElements elements) {
     enqueueInResolution(getThrowNoSuchMethod(), elements);
+    compiler.enqueuer.resolution.registerInstantiatedClass(

[ahe, 2013/08/15 11:27:43]

Please document that these represent the arguments passed to this method.

[ngeoffray, 2013/08/15 11:31:34]

Done.

+        compiler.listClass, elements);
+    enqueuer.registerInstantiatedClass(compiler.stringClass, elements);
   }
 
   void registerThrowRuntimeError(TreeElements elements) {
+    enqueuer.registerInstantiatedClass(compiler.stringClass, elements);

[ahe, 2013/08/15 11:27:43]

Ditto.

[ngeoffray, 2013/08/15 11:31:34]

Done.

     enqueueInResolution(getThrowRuntimeError(), elements);
   }
 
   void registerAbstractClassInstantiation(TreeElements elements) {
+    enqueuer.registerInstantiatedClass(compiler.stringClass, elements);

[ahe, 2013/08/15 11:27:43]

Ditto.

[ngeoffray, 2013/08/15 11:31:34]

Done.

     enqueueInResolution(getThrowAbstractClassInstantiationError(), elements);
   }