* merge.c (struct sec_merge_sec_info): Update comment.

	* merge.c (struct sec_merge_sec_info): Update comment.
	(struct sec_merge_hash_entry): Remove entsize.
	(sec_merge_hash_lookup): Only adjust alignment when creating.
	(sec_merge_emit): Remove register keyword.
	(cmplengthentry, last4_eq, last_eq): Delete.
	(strrevcmp, strrevcmp_align, is_suffix): New.
	(merge_strings): Use them to implement fast suffix merging.
	* elf-strtab.c (struct elf_strtab_hash_entry): Update comments.
	Make "len" signed.
	(_bfd_elf_strtab_add): Lose on >2G strings.
	(_bfd_elf_strtab_emit): Don't emit strings with len < 0.
	(cmplengthentry, last4_eq): Delete.
	(strrevcmp, is_suffix): New.
	(_bfd_elf_strtab_finalize): Rework to implement fast suffix merging.