Add crashing test case for for dartbug.com/9664.

tests/language/issue9664_test.dart

Index: tests/language/issue9664_test.dart
diff --git a/tests/compiler/dart2js_native/is_check_test.dart b/tests/language/issue9664_test.dart
similarity index 73%
copy from tests/compiler/dart2js_native/is_check_test.dart
copy to tests/language/issue9664_test.dart
index f0ae31152918cbaf39c6b3f5c54e8358b063c10e..b8b3c2db6b6277c62393bd7e44f03b26292eaf37 100644
--- a/tests/compiler/dart2js_native/is_check_test.dart
+++ b/tests/language/issue9664_test.dart
@@ -2,9 +2,8 @@
 // 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.
 
-class A native "*A" {}
+// Regression test for http://dartbug.com/9664
 
 main() {
-  var a = [new Object()];
-  Expect.isFalse(a[0] is A);
+  while (true ? true : true) break;
 }