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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

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.

Commit log from Dragonfly:

FreeBSD extended ctypes to include numbers (e.g. isnumber()) but never
actually implemented it. The isnumber() function was equivalent to the
isdigit() function in every case.

Now that DragonFly's ctype source files have number definitions, the
number ctype can finally be implemented. It's given a new flag _CTYPE_N.
The isalnum() and iswalnum() functions have been changed to use this
flag rather than the _CTYPE_D digit flag.

While isalnum(), isnumber(), and their wide equivalents now return
different values in locale cases, the ishexnumber() and iswhexnumber()
functions are unchanged. They are still aliases for isxdigit() and
iswxdigit().

Also change ctype.h for isdigit and isxdigit to use sbistype like the
other functions.

Obtained from: dragonfly

Use defined() to test macro definitions.

Approved by: theraven

Fix a bug caused by some misplaced brackets.

Reported by: das

And remove the duplicate inlines...

Approved by: dim (mentor)

Fix the other missing prototypes.

Approved by: dim (mentor)

Add missing prototypes.

Approved by: dim (mentor)

More xlocale cleanups.

Approved by: dim (mentor)

After r232498, programs built with -ansi or -std=c89 including <ctype.h>
would not compile anymore, due to plain 'inline' keywords. Fix this by
using __inline instead.

Reported by: Jia-Shiun Li <jiashiun@gmail.com>
Discussed with: theraven

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

Approved by: dim (mentor)

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)