Most of the remaining multi-arch conversion work for the ARM is 
target-specific.  Below is an initial stab at detecting the various object 
formats that I know about.  It seems that, even for ELF, this isn't an 
exact science -- There is a fairly-well defined flag in the elf header 
(EI_OSABI), but no-one seems to set it reliably, certainly gas/gld don't!  
I'd appreciate comments from anyone who has been through this gloop before.

If nobody yells loudly, I'll probably commit this sometime tomorrow.

R.

	* arm-tdep.h (enum arm_abi): New.
	(struct gdbarch_tdep): New.
	(LOWEST_PC): Define if not previously defined; use multi-arch 
	tdep variable.
	* config/arm/tm-arm.h (LOWEST_PC): Delete.
	* config/arm/tm-nbsd.h (LOWEST_PC): Delete.
	* armnbsd-nat.c: Include regcache.h.
	* arm-tdep.c: Include elf/arm.h.
	(process_note_abi_tag_sections): New function.
	(get_elfosabi): New function.
	(arm_gdbarch_init): Try to determine the type of object we've been
	handed and set the ABI up appropriately.
	(arm_dump_tdep): Dump target-dependent data.
	(_initialize_arm_tdep): Register arm_dump_tdep.
	* Makefile.in (armnbsd-nat.c, arm-tdep.c): Update dependencies.