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

langinfo.h: Hide YESSTR and NOSTR in strict POSIX mode.

YESSTR and NOSTR are obsolete and are only in old SUS.

Correctly expose xlocale functions if people include the headers in the wrong
order (as some ports apparently do).

Approved by: dim (mentor)

Reapply 227753 (xlocale cleanup), plus some fixes so that it passes build
universe with gcc.

Approved by: dim (mentor)

Revert r231673 and r231682 for now, until we can run a full make
universe with them. Sorry for the breakage.

Pointy hat to: me and brooks

Cleanup of xlocale:

- Address performance regressions encountered by das@ by caching per-thread
data in TLS where available.
- Add a __NO_TLS flag to cdefs.h to indicate where not available.
- Reorganise the xlocale.h definitions into xlocale/*.h so that they can be
included from multiple places.
- Export the POSIX2008 subset of xlocale when POSIX2008 says it should be
exported, independently of whether xlocale.h is included.
- Fix the bug where programs using ctype functions always assumed ASCII unless
recompiled.
- Fix some style(9) violations.

Reviewed by: brooks (mentor)
Approved by: dim (mentor)

Modified locale(1) to be able to show the altmon_X fields and the [cxX]_fmt's.
Also modify the "-k list" option to display only fields with a certain prefix.

MFC after: 1 week

o Don't include <nl_types.h>, instead provide a typedef for nl_item.
o Use relatively new visibility primitives to conditionalize some
constants.

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.

* style(9)'ify
* add K&R support to langinfo.h

Requested by: bde (2)

Add my e-mail to copyrights

Add D_MD_ORDER (local extension) to get month/day order from locale

Add SUSv2 compatible nl_langinfo() function. It still need some work, but
this is already usable one.