[cpp] Add socket setFastSend

std/cpp/_std/sys/net/Socket.hx

@@ -211,7 +211,7 @@ class Socket {
 	}
 
 	public function setFastSend( b : Bool ) : Void {
-		throw "Not implemented";
+		socket_set_fast_send(__s,b);
 	}
 
 	public static function select(read : Array<Socket>, write : Array<Socket>, others : Array<Socket>, ?timeout : Float ) : {read: Array<Socket>,write: Array<Socket>,others: Array<Socket>} {
@@ -239,5 +239,6 @@ class Socket {
 	private static var socket_set_timeout = cpp.Lib.load("std","socket_set_timeout",2);
 	private static var socket_shutdown = cpp.Lib.load("std","socket_shutdown",3);
 	private static var socket_set_blocking = cpp.Lib.load("std","socket_set_blocking",2);
+	private static var socket_set_fast_send = cpp.Lib.loadLazy("std","socket_set_fast_send",2);
 
 }