* shnbsd-tdep.c: Include "regset.h", "gdb_assert.h" and

	* shnbsd-tdep.c: Include "regset.h", "gdb_assert.h" and
	"gdb_string.h".  Don't include "nbsd-tdep.h".
	(SIZEOF_STRUCT_REG): Remove.
	(SHNBSD_SIZEOF_GREGS): New.
	(shnbsd_supply_gregset, shnbsd_collect_gregset)
	(shnbsd_regset_from_core_section): New functions.
	(fetch_core_registers, fetch_elfcore_registers): Remove functions.
	(shnbsd_supply_reg, shnbsd_fill_reg): Simply call
	shnbsd_supply_gregset, shnbsd_collect_gregset.
	(shnbsd_gregset): New variable.
	(shnbsd_init_abi): Set regset_from_core_section.
	(GDB_OSABI_NETBSD_CORE): New define.
	(shnbsd_core_osabi_sniffer): New function.
	(_initialize_shnbsd_tdep): Register shnbsd_core_osabi_sniffer.
	* Makefile.in (shnbsd-tdep.o): Update dependencies.
	* config/sh/nbsd.mt (TDEPFILES): Add corelow.o, remove
	nbsd-tdep.o.
	* config/sh/obsd.mt (TDEPFILES): Remove nbsd-tdep.o.