Move all tests using dart:io to a separate directory

tests/standalone/src/Regress-1925.dart

-// Copyright (c) 2012, 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.
-//
-// Regression test for http://code.google.com/p/dart/issues/detail?id=1925.
-//
-// VMOptions=
-// VMOptions=--short_socket_read
-// VMOptions=--short_socket_write
-// VMOptions=--short_socket_read --short_socket_write
-
-#import("dart:io");
-#import("dart:isolate");
-#source("TestingServer.dart");
-
-final CONNECTIONS = 200;
-
-class Regress1925TestServer extends TestingServer {
-
-  void onConnection(Socket socket) {
-    socket.onError = () => Expect.fail("Server socket error");
-    socket.inputStream.onClosed = () => socket.outputStream.close();
-    socket.inputStream.onData = () {
-      var buffer = new List(1);
-      var read = socket.inputStream.readInto(buffer);
-      Expect.equals(1, read);
-      socket.outputStream.writeFrom(buffer, 0, read);
-    };
-  }
-
-  int _connections = 0;
-}
-
-
-class Regress1925Test extends TestingServerTest {
-  Regress1925Test.start() : super.start(new Regress1925TestServer());
-
-  void run() {
-
-    void onConnect() {
-      _connections++;
-      if (_connections == CONNECTIONS) {
-        for (int i = 0; i < CONNECTIONS; i++) {
-          _sockets[i].close();
-        }
-        shutdown();
-      }
-    }
-
-    var count = 0;
-    var buffer = new List(5);
-    Socket socket = new Socket(TestingServer.HOST, _port);
-    socket.onConnect = () {
-      socket.outputStream.write("12345".charCodes());
-      socket.outputStream.close();
-      socket.inputStream.onData = () {
-        count += socket.inputStream.readInto(buffer, count);
-      };
-      socket.inputStream.onClosed = () {
-        Expect.equals(5, count);
-        shutdown();
-      };
-      socket.inputStream.onError = () => Expect.fail("Socket error");
-    };
-  }
-}
-
-main() {
-  Regress1925Test test = new Regress1925Test.start();
-}