Fix build:

tests/isolate/error_at_spawnuri_test.dart

Index: tests/isolate/error_at_spawnuri_test.dart
diff --git a/tests/isolate/error_at_spawnuri_test.dart b/tests/isolate/error_at_spawnuri_test.dart
index 791992490fc0ed3448b68040c97e703b625e3419..1edcdf74346cc8898c27572f70346b074a563c35 100644
--- a/tests/isolate/error_at_spawnuri_test.dart
+++ b/tests/isolate/error_at_spawnuri_test.dart
@@ -1,6 +1,8 @@
 // Copyright (c) 2015, 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.
+//
+// OtherScripts=error_at_spawnuri_iso.dart
 
 library error_at_spawnuri;