Correct and GC unrecognized flags from our tests.

tests/language/enum_test.dart

Index: tests/language/enum_test.dart
diff --git a/tests/language/enum_test.dart b/tests/language/enum_test.dart
index 0e41965ac5f1837361883ba64007eeaed4f641c3..a3b458632d92dbd9f03c07c1d89f524f79fb8637 100644
--- a/tests/language/enum_test.dart
+++ b/tests/language/enum_test.dart
@@ -2,8 +2,6 @@
 // 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.
 
-// SharedOptions=--enable-enum
-
 import 'package:expect/expect.dart';
 
 enum Enum1 { _ }
@@ -112,4 +110,4 @@ test5(Enum5 e) {
       break;
   }
   Expect.equals(e.index, index);
-}
+}