Fix test for checked mode.

Review URL: https://codereview.chromium.org//22862008

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@26118 260f80e4-7a28-3924-810f-c04153c831b5

tests/language/issue12284_test.dart

@@ -19,5 +19,6 @@ class A {
 
 main() {
   Expect.equals(42 + 42, new A(42).field);
-  Expect.throws(() => new A.redirect(), (e) => e is ArgumentError);
+  Expect.throws(() => new A.redirect(),
+                (e) => e is ArgumentError || e is TypeError);
 }