Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Add CFI start/end proc directives to arm64, i386, and ppc

Follow-up to r353959 and r368070: do the same for other architectures.

arm32 already seems to use its own .fnstart/.fnend directives, which
appear to be ARM-specific variants of the same thing. Likewise, MIPS
uses .frame directives.

Reviewed by: arichardson
Differential Revision: https://reviews.freebsd.org/D27387

Add section .note.GNU-stack for assembly files used by 386 and amd64.

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

Use __FBSDID() instead of RCSID() in most .S files under lib/msun/i386,
and one under lib/msun/amd64. This avoids adding the identifiers to the
.text section, and moves them to the .comment section instead.

Suggested by: bde
Approved by: rpaulo (mentor)

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.

MD implementations of sqrtl().