Remove references to ObjectNotClosureException and ClosureArgumentMismatchException

runtime/lib/errors_patch.dart

Index: runtime/lib/errors_patch.dart
===================================================================
--- runtime/lib/errors_patch.dart	(revision 14360)
+++ runtime/lib/errors_patch.dart	(working copy)
@@ -8,15 +8,3 @@
   }
 }
 
-// Exceptions that should be NoSuchMethodError instead.
-
-class _ClosureArgumentMismatchException implements Exception {
-  const _ClosureArgumentMismatchException();
-  String toString() => "Closure argument mismatch";
-}
-
-
-class _ObjectNotClosureException implements Exception {
-  const _ObjectNotClosureException();
-  String toString() => "Object is not closure";
-}