Fix cacthing exception object: a null exception is always caught.

tests/language/src/ExceptionTest.dart

Index: tests/language/src/ExceptionTest.dart
===================================================================
--- tests/language/src/ExceptionTest.dart	(revision 4404)
+++ tests/language/src/ExceptionTest.dart	(working copy)
@@ -18,6 +18,12 @@
       i += 10;
     }
     Expect.equals(20, i);
+
+    try {
+      throw null;
+    } catch (String s) {
+      // null exception object is caught here.

[hausner, 2012/02/21 21:47:48]

Actuall one more comment. Maybe have two catch clauses here and check that the
first one is executed.

[srdjan, 2012/02/21 21:53:52]

Done.

+    }
   }
 }