insight 5.0 gdbserver on ARM build problems

[Paul Kinzelman]

I found that somebody inserted the string "# OBSOLETE" in the
.../gdb/config/arm/arm.mt and .mh files, thereby breaking the
build for ARM.

Also, there are lots of header files missing when I do a standard
config and build, the -I path probably needs fixing:
stdio.h, errno.h, unistd.h, stdlib.h, setjmp.h, string.h, endian.h

And lastly (at least as far as I've gotten), the
DECR_PC_AFTER_BREAK definition needs to be 4 in tm-arm.h
-PaulK