Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

rtld-elf/libmap.h: style declarations

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

rtld-elf/libmap.h: add include guard

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

rtld: constify most variables holding references to the environment values

Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31545

rtld-elf: make it compile with WARNS=3

Reviewed By: kib
Approved By: brooks (mentor)
Differential Revision: https://reviews.freebsd.org/D17150

Make the directory mapping functionality, which was previously only
available in 32-bit compatibility mode, unconditional.

Overhaul the man page, which had evolved more by accretion than by design.

Approved by: re (gjb)
MFC after: 3 weeks

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.

Description from Dan:

Another handy libmap patch. Lets you do stuff like this:

LD_LIBMAP="libpthread.so.1=libthr.so.1" mythreadedapp

If you already have a program-specific override in libmap.conf, note
that you must use a program-specific override in LD_LIBMAP:

LD_LIBMAP="[mythreadedapp],libpthread.so.1=libthr.so.1" mythreadedapp

PR: bin/74471
Submitted by: Dan Nelson <dnelson AT allantgroup.com>
MFC after: 2 weeks

Add initial support for compiling a special 32 bit version of
ld-elf.so.1 on 64 bit systems. Most of this involves using alternate
paths, environment variables and diagnostic messages.

The build glue is seperate.

Change libmap.c:lm_init() to return a status value; 0 for success
(libmap available) and 1 for failure. Assign this return to the
global 'libmap_disable' variable in rtld.c.

This totally prevents any libmap functions from being called after
lm_init() if no config file is present.

Dynamic object dependency mapping: libmap.

This is an optional feature, disabled by default.

This will be useful to people testing the various POSIX threading
libraries under -CURRENT but can easily serve other needs.