bring over local mods from gdb5:
 - use the right LWP ID with ptrace.
 - implement single stepping.
disable sim for mips until someone adds the rest of the build framework for it.
rerun mknative (disabling sim).
switch the rest of the architectures to gdb6.
Add acorn26/mutex.h and acorn26/rwlock.h.
don't do the weak symbol thing in kernel context.
switch from kqueue() back to pollts() so that signals will be unblocked
while we're sleeping.  keep the new timeout logic, though.
as discussed on source-changes some 15 months ago.
Complete the ANSI conversion by completing the conversion of hpux_sys_rtprio().
in pmap_extract(), check for the PTE being valid in addition to
the PTP being valid when deciding if a user mapping exists.
We have to bus_mapmap_load() after m_adj, otherwise the map will point at
the wrong place in the buffer. Fix an issue in the !sc->bge_rx_alignment_bug
case reported by Nicolas Joly.
While there remove a duplicate m_adj(), and add a missing bus_dmamap_unload().
Add regression tests for sdiff(1).
From OpenBSD.
Support the sq(4) interface on the Challenge S's IOPLUS mezzanine. This
requires us to configure the IOPLUS to use the appropriate DMA channel,
depending on what other expansion cards may be installed. Further, we need
to do a bit more configuration of the sq(4) DMA engine, which apparently
was formerly being configured properly by the PROM. Use the same values,
which appear to work fine.

Also, extend the gio_arb_config interface as needed.

NB: We're currently setting the IOPLUS board to long burst, but it may be
better to use realtime. This will require some experimentation.
Add options SYSCALL_{STATS,TIMES,TIMES_HASCOUNTER}.
Fix fallout from if_output constification.  Thanks, Havard Eidnes,
for reporting the problem and testing my patch.
Remove unused #define SIN().  From he@.
Move softintr_init from irq_init to cpu_configure.
Make softintr_names const.
Don't do softinit_init from irq_init.
Fix checks for 64-bit MIPS (MIPS64 _doesn't_ mean 64-bit MIPS(!)).
* combine emulation layer tasks for node creation to a common routine
* make set/getattr easily callable from interface functions and sprinkle
  calls to locations which require them
* use libpuffs routine for stat->vattr translation instead of homegrown one
* I have concluded that we really want to do release/releasedir in
  inactive instead of reclaim.  make it so.  we'll tweak it for the next
  file system which decides it doesn't want to work

after these changes lzofs works, at least for most parts
(I'd assume the non-working parts to fail also on fuse/linux)