Make temp directory start with dart_ in file_stream test. Fix DOS line endings.

tests/standalone/io/http_server_close_response_after_error_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.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
 
 import 'dart:async';
@@ skipping 16 matching lines @@
         Process.run(Platform.executable,
                     [Platform.script.resolve(CLIENT_SCRIPT).toString(),
                      server.port.toString()])
             .then((result) {
               if (result.exitCode != 0) throw "Bad exit code";
               server.close();
             });
       });
 }