* sparc-tdep.h: New file.
* sparc-tdep.c (elf-bfd.h): Include.
(SPARC_HAS_FPU, FP_REGISTER_BYTES, FP_MAX_REGNUM,
SPARC_INTREG_SIZE, DUMMY_REG_SAVE_OFFSET, gdbarch_tdep,
CALL_DUMMY_CALL_OFFSET): Move out to sparc-tdep.h
(sparc_dump_tdep): New function.
(_initialize_sparc_tdep): Use gdbarch_register instead of
register_gdbarch_init which is deprecated.
(process_note_abi_tag_sections, sparc_abi_handler,
sparc_abi_handler_list, sparc_gdbarch_register_os_abi): New.
(sparc_gdbarch_init): Determine elf os ident key based upon
either the elf header or by using process_note_abi_tag_sections.
Fix 'gdbarch already exists' test by comparing os_ident as well.
As the last action, invoke OS abi_handler if installed.