Address compiler warnings in C code used by the DTrace test suite.

Reported by: Jenkins
MFC after: 1 week

Ensure that we use a 64-bit value for the last mmap() argument.

When using __syscall(2), the offset argument is passed on the stack on
amd64. Previously only 32 bits were written, so the upper 32 bits were
garbage and could cause the test to fail.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Use __syscall(2) rather than syscall(2) in syscall/tst.args.c.

Some of mmap(2)'s arguments are 64 bits wide.

MFC after: 3 days

Include required headers in DTrace test programs.

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.