cluster: handle bind errors on Windows

Before sending a socket from a cluster master to a worker,
we would call listen in UV but not handle the error.

I made createServerHandle call listen on Windows so we get a chance
the handle any bind/listen errors early.

This fix is 100% windows specific.
It fixes test-cluster-bind-twice and
test-cluster-shared-handle-bind-error on Windows.

lib/net.js

@@ -999,6 +999,12 @@ exports.Server = Server;
 
 function toNumber(x) { return (x = Number(x)) >= 0 ? x : false; }
 
+function _listen(handle, backlog) {
+  // Use a backlog of 512 entries. We pass 511 to the listen() call because
+  // the kernel does: backlogsize = roundup_pow_of_two(backlogsize + 1);
+  // which will thus give us a backlog of 512 entries.
+  return handle.listen(backlog || 511);
+}
 
 var createServerHandle = exports._createServerHandle =
     function(address, port, addressType, fd) {
@@ -1046,6 +1052,17 @@ var createServerHandle = exports._createServerHandle =
     return err;
   }
 
+  if (process.platform === 'win32') {
+    // On Windows, we always listen to the socket before sending it to
+    // the worker (see uv_tcp_duplicate_socket). So we better do it here
+    // so that we can handle any bind-time or listen-time errors early.
+    err = _listen(handle);
+    if (err) {
+      handle.close();
+      return err;
+    }
+  }
+
   return handle;
 };
 
@@ -1054,6 +1071,8 @@ Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
   debug('listen2', address, port, addressType, backlog);
   var self = this;
 
+  var alreadyListening = false;
+
   // If there is not yet a handle, we need to create one and bind.
   // In the case of a server sent via IPC, we don't need to do this.
   if (!self._handle) {
@@ -1066,6 +1085,7 @@ Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
       });
       return;
     }
+    alreadyListening = (process.platform === 'win32');
     self._handle = rval;
   } else {
     debug('_listen2: have a handle already');
@@ -1074,10 +1094,9 @@ Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
   self._handle.onconnection = onconnection;
   self._handle.owner = self;
 
-  // Use a backlog of 512 entries. We pass 511 to the listen() call because
-  // the kernel does: backlogsize = roundup_pow_of_two(backlogsize + 1);
-  // which will thus give us a backlog of 512 entries.
-  var err = self._handle.listen(backlog || 511);
+  var err = 0;
+  if (!alreadyListening)
+    err = _listen(self._handle, backlog);
 
   if (err) {
     var ex = errnoException(err, 'listen');