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 NetBSD Foundation clauses 3 & 4. They eliminated those clauses
last year.

Analogous to __printflike and __scanflike, add the macro __format_arg which
expands to the GCC format_arg attribute if supported.

This fixes a syntax error in <nl_types.h> for compilers/tools not
implementing the GCC __attribute__ extensions.

Bring in NetBSD's improvements and cleanups to NLS subsystem, making
it type and endian clean and removing of stdio dependency from NLS
functions (catalog files now are processed via mmap()).

Also following changes were done (against NetBSD version):

. ANSI'fy prototypes
. Mention FreeBSD in comments
. Pull in sys/types.h instead of sys/_types.h since some types used here
are defined in sys/types.h

Obtained from: NetBSD (mostly)

Add forgotten <sys/_types.h> include. Fix some style bugs while I'm
here.

PR: 43326

Move definition of nl_item type to <sys/_types.h>, so that it can be
shared.

Breath deep and take __P out of the system include files.

# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.

$Id$ -> $FreeBSD$

Protect declarations for C++ users.

Submitted by: Richard Wiwatowski <rjwiwat@ozemail.com.au>

Prototypes/typedefs cleanup
Add NL_CAT_LOCALE (will be implemented soon)

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Remove trailing whitespace.

Add a necessary include file for the catgets* routines.
Obtained from: NetBSD