Support new malformed types semantics.

tests/language/is_not_class2_test.dart

Index: tests/language/is_not_class2_test.dart
diff --git a/tests/language/is_not_class2_negative_test.dart b/tests/language/is_not_class2_test.dart
similarity index 76%
rename from tests/language/is_not_class2_negative_test.dart
rename to tests/language/is_not_class2_test.dart
index 3883910b12f583049394d69cf53384a50f08f0ee..710c72ddfbb6d95cb5190cfd6178091f7cb6293b 100644
--- a/tests/language/is_not_class2_negative_test.dart
+++ b/tests/language/is_not_class2_test.dart
@@ -1,7 +1,10 @@
 // Copyright (c) 2011, 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.
-// Dart test program for catch that we expect a class after an 'is'.
+
+// Dart test program for catch that we expect a class after an 'is'. This is
+// not a negative test since 'aa' is a malformed type and therefore should be
+// treated as dynamic.
 
 class A {
   const A();
@@ -12,7 +15,7 @@ class IsNotClass2NegativeTest {
     var a = new A();
     var aa = new A();
 
-    if (a is aa) {
+    if (a is aa) { // static warning
       return 0;
     }
     return 0;