Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Merge from tbemd:

Convert from using MACHINE_ARCH to MACHINE_CPUARCH. Hoist path statement
up into the top Makefile rather than repeating it on every arch Makefile.

Repo copy libpthreads to libkse.
This introduces the WITHOUT_LIBKSE nob,
and changes WITHOUT_LIBPTHREADS to mean with neither threading libs.
Approved by: re(kensmith)

PPC MD bits for KSE. Runs test cases OK. Crippled to 1:1 mode for
the time being.