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/

typo: suppported.

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.

libc: do not include <sys/types.h> where <sys/param.h> was already included

According to style(9):
> normally, include <sys/types.h> OR <sys/param.h>, but not both.
(<sys/param.h> already includes <sys/types.h> when LOCORE is not defined).

Use ANSI C prototypes. Eliminates -Wold-style-definition warnings.

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.

Make inet6_rth_* family of functions more compliant with RFC3542:
1. CMSG_NXTHDR(mhdr, cmsg) is supposed to dereference cmsg and return
the next header in the chain. If cmsg is NULL it should return
the first header, behaving essentially like CMSG_FIRSTHDR().
2. inet6_rth_(space|init|add) should do basic checking on their input
to verify that the number of headers (segments) is
between 0 and 127 inclusive.

MFC-After: 1 month

refer RFC 3542 rather than RFC 2292bis.

Submitted by: Keiichi SHIMA <keiichi__at__iijlab.net>
Obtained from: KAME

fixed the validation code of routing header length in inet6_rth_getaddr().
reported by Delia Kecskemeti <delia.kecskemeti__at__windriver.com>

Submitted by: Keiichi SHIMA <keiichi__at__iijlab.net>
Obtained from: KAME

Switch Advanced Sockets API for IPv6 from RFC2292 to RFC3542
(aka RFC2292bis). Though I believe this commit doesn't break
backward compatibility againt existing binaries, it breaks
backward compatibility of API.
Now, the applications which use Advanced Sockets API such as
telnet, ping6, mld6query and traceroute6 use RFC3542 API.

Obtained from: KAME

just merged cosmetic changes from KAME to ease sync between KAME and FreeBSD.
(based on freebsd4-snap-20020128)

Reviewed by: ume
MFC after: 1 week

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Remove 'register' keyword.

CMSG_XXX macros alignment fixes to follow RFC2292.

Approved by: jkh

Submitted by: Partly from tech@openbsd
Reviewed by: itojun

KAME 4th patch
IPv6 specific library functions addition.
(getnameinfo(), getaddrinfo(), and IPv6 transport support is not yet)

Reviewed by: freebsd-arch, cvs-committers
Obtained from: KAME project