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/

The posix_madvise(3) and posix_fadvise(2) should return error on
failure, same as posix_fallocate(2).

Noted by: Bob Bishop <rb@gid.co.uk>
Discussed with: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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.

Add the POSIX 1003.1-2001 posix_madvise() interface.

PR: standards/54634
Reviewed by: das
Approved by: jake (mentor)

Fix SCM ID's.

Add a couple of new library interfaces (will be activated when the
relavant header file changes are committed) for POSIX support.