* sysdeps/mach/hurd/bits/socket.h: Include <bits/wordsize.h> instead
of <limits.h>
(__need_NULL): Do not define.
(__ss_aligntype): Use __WORDSIZE instead of ULONG_MAX to determine
alignment.
[!__USE_MISC] (pseudo_AF_XTP, pseudo_AF_RTIP, pseudo_AF_PIP,
CMGROUP_MAX, cmsgcred): Do not define.
(CMSG_FIRSTHDR, __cmsg_nxthdr): Use (struct cmsghdr *) 0 instead of
NULL.
* bits/socket.h: Likewise.