Update the test runner to use the new dart:io API

tests/standalone/standalone.status

 # 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.
 
 package/invalid_uri_test: Fail, OK # Fails intentionally
 
 [ $runtime == vm ]
 # Temporarily disabled until the test scripts are rewritten for
 # dart:io v2.
 io/skipping_dart2js_compilations_test: skip # Non-fatal process error.
-io/status_file_parser_test: fail
-io/test_runner_exit_code_test: fail
-io/test_runner_test: fail
 
 [ $compiler == dartc ]
 io/skipping_dart2js_compilations_test: Fail  # Date-to-DateTime renaming. Also fails on VM above.
-io/test_runner_test: Fail  # Date-to-DateTime renaming. Also fails on vm above.
 
 
 [ $runtime == vm && ( $system == windows ) ]
 io/raw_socket_test: Pass, Fail # Issue 8901
 
 [ $runtime == vm ]
 package/package_isolate_test: Fail # http://dartbug.com/7520.
 io/raw_server_socket_cancel_test: Pass, Fail, Timeout # Issue 8675
 
 # Fails with a connection refused error on the buildbot.
@@ skipping 104 matching lines @@
 *: Skip
 
 [ $arch == simarm ]
 *: Skip
 
 [ $arch == mips ]
 *: Skip
 
 [ $arch == simmips ]
 *: Skip