generic remote support for arm-aout

[Stu Grossman]

 >    Also, since the ARM architecture doesn't support
 >    h/w single stepping (or does it?), I've #define'd
 >    NO_SINGLE_STEP in tm-arm.h and added the
 >    following single_step() function to arm-tdep.c:
 > 
 > I'd want to doublecheck that this doesn't interfere with h/w single-step
 > that's part of adp (rdi) and rdp protocols, but I don't think there's
 > a problem.

Actually, the best solution here is to implement single-step in the stub, and
hide any implementation specific details in there, where they are most easily
handled.  For ARM implementations that don't support hardware single-step, it
can be simulated in the stub using breakpoints, which is *much* faster than
doing the same via GDB's remote protocol.

			Stu