libc: Purge unneeded cdefs.h

These sys/cdefs.h are not needed. Purge them. They are mostly left-over
from the $FreeBSD$ removal. A few in libc are still required for macros
that cdefs.h defines. Keep those.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D42385

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\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spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD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

libc: drop "All rights reserved" from Foundation copyrights

This has already been done for most files that have the Foundation as
the only listed copyright holder. Do it now for files that list
multiple copyright holders, but have the Foundation copyright in its own
section.

Sponsored by: The FreeBSD Foundation

libc: 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.

Fix typo in the r320472 change to fgetws(). Return proper value.

Reported by: Oleg Ginzburg <olevole@olevole.ru>
Reviewed by: vangyzen
Sponsored by: The FreeBSD Foundation
MFC after: 13 days

Make stdio deferred cancel-safe.

If used with fopen(3)/fdopen(3)-ed FILEs, stdio accurately uses
non-cancellable internal versions of the functions, i.e. it seems to
be fine with regard to cancellation. But if the funopen(3) and
f{r,w}open(3) functions were used to open the FILE, and corresponding
user functions create cancellation points (they typically have no
other choice), then stdio code at least leaks FILE' lock.

The change installs cleanup handler which unlocks FILE. Some minimal
restructuring of the code was required to make it use common return
place to satisfy hand-rolled pthread_cleanup_pop() requirements.

Noted by: eugen
Reviewed by: eugen, vangyzen
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D11246

Fix n == 1 case. Here should be no physical read (fill buffer) attempt
(we read n - 1 chars with the room for NUL, see fgets()),
and no NULL return.

MFC after: 3 days

1) Prevent out of bounds access to ws[-1] (passed buffer) which happens
when the first mb sequence is incomplete and there are not enougn chars in
the read buffer. ws[-1] may lead to memory faults or false results, in
case the memory here contains '\n'.

2) Fix EOF checking I mess in my previos r305406 commit.

MFC after: 3 days

Fix errors handling.

MFC after: 3 days

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)

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

MFC revs 199781,199782,199784,199785,199786:

Eliminate dead stores.

In __mbsconv(), if prec was zero, nconv could have been used
uninitialized. Initialize it to a safe value so that there's no
chance of returning an error if stack garbage happens to be equal to
(size_t)-1 or (size_t)-2.

In svc_raw_reply(), don't leave stat uninitialized if the MSG_ACCEPTED
&& SUCCESS case succeeds. The stack garbage might be zero.

In clnt_raw_create(), avoid minor race condition initializing the
file-scope variable clntraw_private.

Found by: Clang static analyzer

Eliminate more dead stores.

Found by: Clang static analyzer
MFC after: 7 days

- Import the HEAD csup code which is the basis for the cvsmode work.

Next stage of stdio cleanup: Retire __sFILEX and merge the fields back into
__sFILE. This was supposed to be done in 6.0. Some notes:
- Where possible I restored the various lines to their pre-__sFILEX state.
- Retire INITEXTRA() and just initialize the wchar bits (orientation and
mbstate) explicitly instead. The various places that used INITEXTRA
didn't need the locking fields or _up initialized. (Some places needed
_up to exist and not be off the end of a NULL or garbage pointer, but
they didn't require it to be initialized to a specific value.)
- For now, stdio.h "knows" that pthread_t is a 'struct pthread *' to
avoid namespace pollution of including all the pthread types in stdio.h.
Once we remove all the inlines and make __sFILE private it can go back
to using pthread_t, etc.
- This does not remove any of the inlines currently and does not change
any of the public ABI of 'FILE'.

MFC after: 1 month
Reviewed by: peter

Don't add integers to void pointers.

Read directly from the stdio buffer using the new __mbsnrtowcs() interface
instead of making repeated calls to __fgetwc().

Lock the file once per call and use the unlocked fgetwc()/fputwc() variants.

Reimplement the functionality of fgetrune(), fputrune(), and fungetrune()
here in terms of mbrtowc(), wcrtomb(), and the single-byte I/O functions.
The rune I/O functions are about to become deprecated in favour of the
ones provided by ISO C90 Amd. 1 and C99.

Style: One space between "restrict" qualifier and "*".

Basic support for wide character I/O: getwc(), fgetwc(), getwchar(),
putwc(), fputwc(), putwchar(), ungetwc(), fwide().