Add test directive to include other files used by a test in its compiled output directory.

tests/standalone/io/secure_socket_renegotiate_test.dart

 // Copyright (c) 2013, 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.
+//
+// OtherResources=certificates/server_chain.pem
+// OtherResources=certificates/server_key.pem
 
 // This test verifies that client certificates work, if the client and server
 // are in separate processes, and that connection renegotiation works, and
 // can request a client certificate to be sent.
 
 import "dart:async";
 import "dart:convert";
 import "dart:io";
 
 import "package:expect/expect.dart";
@@ skipping 60 matching lines @@
           if (result.exitCode != 0) {
             print("Client failed, stdout:");
             print(result.stdout);
             print("  stderr:");
             print(result.stderr);
             Expect.fail('Client subprocess exit code: ${result.exitCode}');
           }
         });
     });
 }