m68k: __cpu_simple_unlock audit.

- Use `cc' clobbers in asm volatile because they touch the condition
codes.

- Use `memory' clobbers in asm volatile so the compiler doesn't move
up loads and stores in the critical section at _other_ addresses
than the lock so they happen before __cpu_simple_lock or
__cpu_simple_lock_try.

- Not sure if we have any (or if there even are any?) multicore m68k
systems out there, but __cpu_simple_unlock needs __insn_barrier
either way so the compiler doesn't delay loads and stores prior to
__cpu_simple_unlock so they happen after it.

Nix mb_* on m68k.

branches: 1.15.4;
more const.

branches: 1.14.44;
Remove clause 3 and 4 from TNF licenses

branches: 1.13.16; 1.13.18; 1.13.20;
Merge the ppcoea-renovation branch to HEAD.

This branch was a major cleanup and rototill of many of the various OEA
cpu based PPC ports that focused on sharing as much code as possible
between the various ports to eliminate near-identical copies of files in
every tree. Additionally there is a new PIC system that unifies the
interface to interrupt code for all different OEA ppc arches. The work
for this branch was done by a variety of people, too long to list here.

TODO:
bebox still needs work to complete the transition to -renovation.
ofppc still needs a bunch of work, which I will be looking at.
ev64260 still needs to be renovated
amigappc was not attempted.

NOTES:
pmppc was removed as an arch, and moved to a evbppc target.

Merge nick-csl-alignment.

branches: 1.11.6; 1.11.14; 1.11.18; 1.11.22; 1.11.24;
Merge newlock2 to head.

__unused removal on arguments; approved by core.

branches: 1.9.20; 1.9.22;
inline -> __inline

Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

merge ktrace-lwp.

branches: 1.6.12;
De-__P

Move __cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED to machine/types.h
so that they can be used in a namespace-friendly way.

branches: 1.4.2;
Merge the nathanw_sa branch.

branches: 1.3.6; 1.3.14;
On the m68k, the most efficient type for __cpu_simple_lock_t is
an unsigned char, since that is what the `tas' instruction uses.

While I'm here, implement the __cpu_simple_lock family of routines.
Why? One, because they're easy. Two, so Steve can get master/slave
MVME systems talking across the backplane. :-)

Let each platform typedef the new __cpu_simple_lock_t, which should
be the most efficient type used for the atomic operations in the
simplelock structure, and should also be __volatile.

Require that each each MACHINE/MACHINE_ARCH supply a lock.h. This file
contains the values __SIMPLELOCK_LOCKED and __SIMPLELOCK_UNLOCKED, which
replace the old SIMPLELOCK_LOCKED and SIMPLELOCK_UNLOCKED. These files
are also required to supply inline functions __cpu_simple_lock(),
__cpu_simple_lock_try(), and __cpu_simple_unlock() if locking is to be
supported on that platform (i.e. if MULTIPROCESSOR is defined in the
_KERNEL case). Change these functions to take an int * (&alp->lock_data)
rather than the struct simplelock * itself.

These changes make it possible for userland to use the locking primitives
by including <machine/lock.h>.