Add Windows support.

lib/src/executable.dart

 // Copyright (c) 2015, 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.
 
 // TODO(nweiz): This is under lib so that it can be used by the unittest dummy
 // package. Once that package is no longer being updated, move this back into
 // bin.
 library test.executable;
 
 import 'dart:async';
@@ skipping 22 matching lines @@
 /// This defaults to half the available processors, since presumably some of
 /// them will be used for the OS and other processes.
 final _defaultConcurrency = math.max(1, Platform.numberOfProcessors ~/ 2);
 
 /// A merged stream of all signals that tell the test runner to shut down
 /// gracefully.
 ///
 /// Signals will only be captured as long as this has an active subscription.
 /// Otherwise, they'll be handled by Dart's default signal handler, which
 /// terminates the program immediately.
-final _signals = mergeStreams([
-  ProcessSignal.SIGTERM.watch(), ProcessSignal.SIGINT.watch()
-]);
+final _signals = Platform.isWindows
+    ? ProcessSignal.SIGINT.watch()
+    : mergeStreams([
+        ProcessSignal.SIGTERM.watch(),
+        ProcessSignal.SIGINT.watch()
+      ]);
 
 /// Returns whether the current package has a pubspec which uses the
 /// `test/pub_serve` transformer.
 bool get _usesTransformer {
   if (!new File('pubspec.yaml').existsSync()) return false;
   var contents = new File('pubspec.yaml').readAsStringSync();
 
   var yaml;
   try {
     yaml = loadYaml(contents);
@@ skipping 300 matching lines @@
       if (description is! Map) return false;
       var path = description["path"];
       if (path is! String) return false;
 
       print("$version (from $path)");
       return true;
 
     default: return false;
   }
 }