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/

qdivrem: Predict division by zero as false.

Division by zero triggers an arithmetic exception and should not be very
common. Predict this.

No functional change intended.

MFC after: 1 week
Sponsored by: NVIDIA Networking

Add casts and L suffixes to libc quad support, to work around various
-Werror warnings from clang 10.0.0, such as:

lib/libc/quad/fixdfdi.c:57:12: error: implicit conversion from 'long long' to 'double' changes value from 9223372036854775807 to 9223372036854775808 [-Werror,-Wimplicit-int-float-conversion]
if (x >= QUAD_MAX)
~~ ^~~~~~~~
/usr/obj/usr/src/powerpc.powerpc/tmp/usr/include/sys/limits.h:89:19: note: expanded from macro 'QUAD_MAX'
#define QUAD_MAX (__QUAD_MAX) /* max value for a quad_t */
^~~~~~~~~~
/usr/obj/usr/src/powerpc.powerpc/tmp/usr/include/machine/_limits.h:91:20: note: expanded from macro '__QUAD_MAX'
#define __QUAD_MAX __LLONG_MAX /* max value for a quad_t */
^~~~~~~~~~~
/usr/obj/usr/src/powerpc.powerpc/tmp/usr/include/machine/_limits.h:75:21: note: expanded from macro '__LLONG_MAX'
#define __LLONG_MAX 0x7fffffffffffffffLL /* max value for a long long */
^~~~~~~~~~~~~~~~~~~~

and many instances of:

lib/libc/quad/fixunsdfdi.c:73:17: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
toppart = (x - ONE_HALF) / ONE;
^~~~~~~~
lib/libc/quad/fixunsdfdi.c:45:19: note: expanded from macro 'ONE_HALF'
#define ONE_HALF (ONE_FOURTH * 2.0)
^~~~~~~~~~
lib/libc/quad/fixunsdfdi.c:44:23: note: expanded from macro 'ONE_FOURTH'
#define ONE_FOURTH (1 << (LONG_BITS - 2))
^ ~~~~~~~~~~~~~~~
lib/libc/quad/fixunsdfdi.c:73:29: error: shift count >= width of type [-Werror,-Wshift-count-overflow]
toppart = (x - ONE_HALF) / ONE;
^~~
lib/libc/quad/fixunsdfdi.c:46:15: note: expanded from macro 'ONE'
#define ONE (ONE_FOURTH * 4.0)
^~~~~~~~~~
lib/libc/quad/fixunsdfdi.c:44:23: note: expanded from macro 'ONE_FOURTH'
#define ONE_FOURTH (1 << (LONG_BITS - 2))
^ ~~~~~~~~~~~~~~~

ANSIfy libc/quad

Some of these routines exist in both lib/libc/quad/ and sys/libkern/.
r325988 ANSIfied sys/libkern. Update libc/quad to match.

PR: 223641
Reported by: bde
Sponsored by: The FreeBSD Foundation

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.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

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.

Remove 'register' keyword.

Remove trailing whitespace.

BSD 4.4 Lite Lib Sources