Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Remove 'All Rights Reserved' from xlocale FreeBSD Foundation copyrights

Sponsored by: The FreeBSD Foundation

Add collation version support to querylocale(3).

Provide a way to ask for an opaque version string for a locale_t, so
that potential changes in sort order can be detected. Similar to
ICU's ucol_getVersion() and Windows' GetNLSVersionEx(), this API is
intended to allow databases to detect when text order-based indexes
might need to be rebuilt.

The CLDR version is extracted from CLDR source data by the Makefile
under tools/tools/locale, written into the machine-generated Makefile
under shared/colldef, passed to localedef -V, and then written into
LC_COLLATE file headers. The initial version is 34.0.
tools/tools/locale was recently updated to pull down 35.0, but the
output hasn't been committed under share/colldef yet, so that will
provide the first observable change when it happens. Other versioning
schemes are possible in future, because the format is unspecified.

Reviewed by: bapt, 0mp, kib, yuripv (albeit a long time ago)
Differential Revision: https://reviews.freebsd.org/D17166

include: General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

LC_*_MASK bit shifting order was partially broken from the initial commit
time at year 2012. Only LC_COLLATE_MASK and LC_CTYPE_MASK are in the
right order.

The order here should match XLC_* from "xlocale_private.h" which, in turn,
match LC_* publicly visible order from <locale.h> which determines how
locale components are stored in the structure.
LC_*_MASK -> XLC_* translation done as "ffs(mask) - 1" in the querylocale()
and equivalent shift loop in the newlocale(), so mapped to some wrong
components (excluding two mentioned above).

Formally the fix is ABI breakage, but old code using those masks
never works properly in any case.
Only newlocale() and querylocale() are affected.

MFC after: 7 days

Change the return type of freelocale(3) to void.

Our version of this function currently returns an integer indicating
failure or success, whereas POSIX specifies that this function has no
return value. It returns void. Patch up the header, sources and man page
to use the right type. While there, use the opportunity to simplify the
body of this function.

Theoretically speaking, this change breaks the ABI of this function.
That said, I have yet to find any code that makes use of freelocale()'s
return value. I couldn't find any of it in the base system, nor did an
exp-run reveal any breakage caused by this change.

PR: 211394 (exp-run)

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)