* arm-tdep.h: Add multiple inclusion protection.

* arm-tdep.h: Add multiple inclusion protection.
(struct gdbarch): Add forward declaration.
(armobsd_regset_from_core_section): New prototype.
* armbsd-tdep.c: New file.
* armobsd-tdep.c: Include "gdb_string.h".
(armobsd_init_abi): Set regset_from_core_section.
(armobsd_core_osabi_sniffer): New function.
(_initialize_armobsd_tdep): Register armobsd_core_osabi_sniffer.
* Makefile.in (ALLDEPFILES): Add armbsd-tdep.c.
(armbsd-tdep.o): New dependency.
(armnbsd-tdep.o): Update dependencies.
* config/arm/obsd.mt (TDEPFILES): Add armbsd-tdep.o and corelow.o.