[9fans] breakpoint and single step on ARM

[Richard Miller <9fans@hamnavoe.com>]

A couple of patches applied yesterday should make debugging on ARM a
bit more reliable.  Using db or acid on ARM, you may have noticed that
a program being debugged would sometimes execute through a breakpoint
without stopping, or run away while being single stepped.  It turns out,
as often happens, that one symptom had two separate causes.  For details:
	/n/sources/patch/applied/5db-condcode/readme
	/n/sources/patch/applied/arm-bkpt-cond/readme

To take advantage of the patches, rebuild libmach.a, then acid and db.
On machines with a kw kernel (sheevaplug et al), you'll also want to
rebuild /arm/9plug; otherwise breakpoints will stop working at all.
The new 9plug will, however, still work with the old libmach; and
the bcm and teg2 kernels are already compatible with the new libmach.