MFC r357223:

Merge r357222 from the clang1000-import branch:

Fix the following -Werror warning from clang 10.0.0 in rbootd:

libexec/rbootd/rmpproto.c:335:49: error: multiple unsequenced modifications to 'filename' [-Werror,-Wunsequenced]
filename = (filename = strrchr(filepath,'/'))? ++filename: filepath;
~ ^

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove the 3rd clause ("advertising clause") of the BSD license as
permitted by the University of Berkeley on July 22, 1999.

Reviewed by: imp
MFC after: 1 week

Rework all non-contributed files that use `struct timezone'.

This structure is not part of POSIX. According to POSIX, gettimeofday()
has the following prototype:

int gettimeofday(struct timeval *restrict tp, void *restrict tzp);

Also, POSIX states that gettimeofday() shall return 0 (as long as tzp is
not used). Remove dead error handling code. Also use NULL for a
nul-pointer instead of integer 0.

While there, change all pieces of code that only use tv_sec to use
time(3), as this provides less overhead.

Spelling fixes for libexec/

Include <netinet/in.h> for ntoh*() and hton*() prototypes.

Approved by: das (mentor)

o __P removal
o register removal
o use new style prototypes and function definitions

L_SET -> SEEK_SET

Obtained from: OpenBSD

$Id$ -> $FreeBSD$

Remove no longer needed FreeBSD specific code.

PR: 5497
Submitted by: Jacob Bohn Lorensen <jacob@jblhome.ping.mk>
Obtained from: OpenBSD (indirectly it seems so just to be safe)

Add usage(), rcsids.

Zap register keyword usage and convert: bcopy -> memmove, bzero -> memset,
index -> strchr, and rindex -> strrchr.

Merge conflicts and make this compile -Wall clean.

This commit was generated by cvs2svn to compensate for changes in r27074,
which included commits to RCS files with non-trunk default branches.

Import of NetBSD's rbootd version 19970629

BSD 4.4 Lite Libexec Sources