LibC: Include additional headers in <arpa/inet.h>

According to the Single UNIX Specification, Version 2 the <arpa/inet.h>
header may optionally include <netinet/in.h> and <inttypes.h>. This
helps with porting software like c-ray that expects this to be the case.

Userland/Libraries/LibC/arpa/inet.h

@@ -27,6 +27,8 @@
 #pragma once
 
 #include <endian.h>
+#include <inttypes.h>
+#include <netinet/in.h>
 #include <sys/cdefs.h>
 #include <sys/socket.h>