lib: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

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/

Fix null pointer subtraction in mergesort()

Clang 13 produces the following warning for this function:

lib/libc/stdlib/merge.c:137:41: error: performing pointer subtraction with a null pointer has undefined behavior [-Werror,-Wnull-pointer-subtraction]
if (!(size % ISIZE) && !(((char *)base - (char *)0) % ISIZE))
^ ~~~~~~~~~

This is meant to check whether the size and base parameters are aligned
to the size of an int, so use our __is_aligned() macro instead.

Also remove the comment that indicated this "stupid subtraction" was
done to pacify some ancient and unknown Cray compiler, and which has
been there since the BSD 4.4 Lite Lib Sources were imported.

MFC after: 3 days

libc: Fix null pointer arithmetic warning in mergesort

This file has other questionable code and "optimizations" (such as copying
one int at a time) that are probably no longer useful, so it might make
sense to replace it with a different implementation at some point.

Reviewed By: jhb
Differential Revision: https://reviews.freebsd.org/D28134

General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

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.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Remove names from prototypes

Add declarations to eliminate -Wmissing-prototypes warnings.

Use ANSI C prototypes.

Eliminates gcc 4.9 warnings.

Add support for some block functions that come from OS X. These are
intended to build with any C compiler.

Reviewed by: pfg
MFC after: 3 weeks

Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic number the clauses 1 through 3,
so follow suit to make comparison easier.

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.

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

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

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

Fix some signed/unsigned comparisons. Fix prototypes while I'm here.

PR: 28890
Submitted by: matthias.andree at web dot de
MFC after: 7 days

Remove __P() usage.

Remove 'register' keyword.

Drop unused labels.

Handle a zero elements argument.

PR: 8566
Submitted by: Archie Cobbs <archie@whistle.com>

Remove trailing whitespace.

BSD 4.4 Lite Lib Sources