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

Use ANSI C prototypes. Eliminates -Wold-style-definition warnings.

Fix copy/paste error in lib/libc/locale/toupper.c.

Submitted by: Kohji Okuno <okuno.kohji@jp.panasonic.com>

Implement xlocale APIs from Darwin, mainly for use by libc++. This adds a
load of _l suffixed versions of various standard library functions that use
the global locale, making them take an explicit locale parameter. Also
adds support for per-thread locales. This work was funded by the FreeBSD
Foundation.

Please test any code you have that uses the C standard locale functions!

Reviewed by: das (gdtoa changes)
Approved by: dim (mentor)

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Include a couple of headers to ensure consistency between the prototype and
the function definition.

Prefer <runetype.h> to <rune.h>, since the latter is going away soon.

Prefix the names of members of _RuneLocale and its sub-structures
with ``__'' to avoid polluting the namespace. This doesn't change the
documented rune interface at all, but breaks applications that accessed
_RuneLocale directly.

Use a binary search to find the range containing a character in
RuneRange arrays. This is much faster when there are hundreds of
ranges (as is the case in UTF-8 locales) and was inspired by a
similar change made by Apple in Darwin.

o Merge <machine/ansi.h> and <machine/types.h> into a new header
called <machine/_types.h>.
o <machine/ansi.h> will continue to live so it can define MD clock
macros, which are only MD because of gratuitous differences between
architectures.
o Change all headers to make use of this. This mainly involves
changing:
#ifdef _BSD_FOO_T_
typedef _BSD_FOO_T_ foo_t;
#undef _BSD_FOO_T_
#endif
to:
#ifndef _FOO_T_DECLARED
typedef __foo_t foo_t;
#define _FOO_T_DECLARED
#endif

Concept by: bde
Reviewed by: jake, obrien

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Megre XPG4 code into libc

Fixed longstanding namespace convolution involving rune_t vs wchar_t.
If _ANSI_SOURCE or _POSIX_SOURCE is defined, then <ctype.h> had to
be included before <stddef.h> or <stdlib.h> to get rune_t declared.
Now rune_t is declared perfectly bogusly in all cases when <ctype.h>
is included.

This change breaks similar (but more convoluted) convolutions in the
stddef.h in gcc distributions. Ports of gcc should avoid using the
gcc headers.

Remove half-dancing solution for signed chars to help finding
POSIXly-incorrect programs.

Move more stuff out to XPG4
Handle negative chars inside runetype/tolower/toupper

Migrate from XPG4 to XPG3 (libxpg4 will be added soon)
Remove big part of my startup_setlocale hack.
Add missing manpage links.

Make not-so-space-eaten locale version:
split modules to bring only neccessary functions,
eliminate sprintf, make reduced startup_locale version.