* elf-bfd.h (struct elf_backend_data): Add elf_backend_write_core_note.

	* elf-bfd.h (struct elf_backend_data): Add elf_backend_write_core_note.
	* elfxx-target.h (elf_backend_write_core_note): Define and use.
	* elf.c (elfcore_write_prpsinfo): Call the above.  Add support for
	32-bit core note on 64-bit target.
	(elfcore_write_prstatus): Likewise.
	(elfcore_write_lwpstatus): Make note_name const.
	(elfcore_write_prfpreg): Likewise.
	(elfcore_write_pstatus): Add support for 32-bit core note on 64-bit
	target.
	* elf32-ppc.c (ppc_elf_write_core_note): New function.
	(elf_backend_write_core_note): Define.
	* elf64-ppc.c (ppc64_elf_write_core_note): New function.
	(elf_backend_write_core_note): Define.