bfd/

bfd/
	* elf-bfd.h (_bfd_elf_gc_mark_rsec, _bfd_elf_gc_mark_reloc): Declare.
	(_bfd_elf_gc_mark): Use elf_gc_mark_hook_fn.
	* elflink.c (init_reloc_cookie, fini_reloc_cookie)
	(init_reloc_cookie_rels, fini_reloc_cookie_rels): New functions,
	split out from...
	(bfd_elf_discard_info): ...here.
	(init_reloc_cookie_for_section): New function.
	(fini_reloc_cookie_for_section): Likewise.
	(_bfd_elf_gc_mark_rsec, _bfd_elf_gc_mark_reloc): New functions,
	split out from...
	(_bfd_elf_gc_mark): ...here.  Use init_reloc_cookie_for_section
	and fini_reloc_cookie_for_section.