Wrap signal listening with try catch to fix Windows

runtime/bin/vmservice/vmservice_io.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.
 
 library vmservice_io;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:isolate';
@@ skipping 26 matching lines @@
     serverFuture = server.shutdown(true).then((_) {
       serverFuture = null;
     });
   } else {
     serverFuture = server.startup().then((_) {
       serverFuture = null;
     });
   }
 }
 
-main() {
-  // Get VMService.
-  service = new VMService();
-  // Start HTTP server.
-  server = new Server(service, _ip, _port);
-  if (_autoStart) {
-    server.startup();
-  }
-
+void registerSignalHandler() {
   bool useSIGQUIT = true;
   // Listen for SIGQUIT.
   if (useSIGQUIT) {
     var io = currentMirrorSystem().findLibrary(const Symbol('dart.io'));
     var c = MirrorSystem.getSymbol('_ProcessUtils', io);
     var m = MirrorSystem.getSymbol('_watchSignalInternal', io);
     var processUtils = io.declarations[c];
     processUtils.invoke(m, [ProcessSignal.SIGQUIT]).reflectee.listen(_onSignal);
   } else {
     ProcessSignal.SIGUSR1.watch().listen(_onSignal);
   }
 }
 
+
+main() {
+  // Get VMService.
+  service = new VMService();
+  // Start HTTP server.
+  server = new Server(service, _ip, _port);
+  if (_autoStart) {
+    server.startup();
+  }
+
+  try {
+    registerSignalHandler();
+  } catch (_) {
+    // Listening for signals will fail on Windows.
+  }
+}