Delete regression test that is too heavy on resources.

tests/standalone/io/process_many_test.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.
-
-#import('dart:io');
-
-endProcesses(processes) {
-  processes.forEach((p) {
-    p.stdin.writeString("line\n");
-    p.onExit = (code) => Expect.equals(0, code);
-  });
-}
-
-main() {
-  var num = 75;
-  var started = 0;
-  var processes = [];
-  for (var i = 0; i < num; i++) {
-    var script = new File("tests/standalone/io/process_many_script.dart");
-    if (!script.existsSync()) {
-      script = new File("../tests/standalone/io/process_many_script.dart");
-    }
-    var p = Process.start(new Options().executable, [script.name]);
-    processes.add(p);
-    p.onStart = () {
-      if (++started == num) endProcesses(processes);
-    };
-  }
-}