net: remove use of arguments in Server constructor

The current implementation uses the arguments object in the Server()
constructor. Since both arguments to Server() are optional, there was a
high likelihood of accessing a non-existent element in arguments, which
carries a performance overhead. This commit replaces the arguments
object with named arguments.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>

lib/net.js

@@ -62,8 +62,8 @@ function isPipeName(s) {
 }
 
 
-exports.createServer = function() {
-  return new Server(arguments[0], arguments[1]);
+exports.createServer = function(options, connectionListener) {
+  return new Server(options, connectionListener);
 };
 
 
@@ -984,23 +984,23 @@ function afterConnect(status, handle, req, readable, writable) {
 }
 
 
-function Server(/* [ options, ] listener */) {
-  if (!(this instanceof Server)) return new Server(arguments[0], arguments[1]);
+function Server(options, connectionListener) {
+  if (!(this instanceof Server))
+    return new Server(options, connectionListener);
+
   events.EventEmitter.call(this);
 
   var self = this;
 
-  var options;
-
-  if (util.isFunction(arguments[0])) {
+  if (util.isFunction(options)) {
+    connectionListener = options;
     options = {};
-    self.on('connection', arguments[0]);
+    self.on('connection', connectionListener);
   } else {
-    options = arguments[0] || {};
+    options = options || {};
 
-    if (util.isFunction(arguments[1])) {
-      self.on('connection', arguments[1]);
-    }
+    if (util.isFunction(connectionListener))
+      self.on('connection', connectionListener);
   }
 
   this._connections = 0;