Fix crash in typechecker

tests/language/regress_21793_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// Regression test for issue 21793.
+
 import 'package:expect/expect.dart';
 
-foo() {
-  try {
-    try {
-      return 1;
-    } catch (e1) {
-    } finally {
-      return 3;
-    }
-  } catch (e2) {
-  } finally  {
-    return 5;
-  }
-}
-
+/*   /// 01: static type warning, runtime error
+class A { call(x) => x; }
+*/   /// 01: continued
 
 main() {
-  Expect.equals(5, foo());
+  print(new A()(499));
 }