Handle @NoInline annotations in closed_world2_test

tests/compiler/dart2js/kernel/closed_world_tester.dart

 // Copyright (c) 2017, 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.
 
 /// Helper application to run `closed_world2_test` on multiple files or
 /// directories.
 
 import 'dart:async';
 import 'dart:io';
 
@@ skipping 14 matching lines @@
       await testFile(new File(path));
     } else {
       print("$arg doesn't exist");
     }
   }
 }
 
 Future testFile(File file) async {
   print('====================================================================');
   print('testing ${file.path}');
-  await mainInternal([file.path]);
+  try {
+    await mainInternal([file.path], skipWarnings: true, skipErrors: true);
+  } catch (e, s) {
+    print('$e:\n$s');
+  }
 }