* bfdlink.h (struct bfd_link_info): Delete emit_note_gnu_build_id.
bfd/
	* configure.in: Bump version to 2.23.52.
	* elf-bfd.h (struct elf_build_id_info): New.
	(struct elf_obj_tdata): Delete after_write_object_contents,
	after_write_object_contents_info and build_id_size.  Make build_id
	a pointer to struct elf_build_id_info.
	* elf.c (_bfd_elf_write_object_contents): Style.  Update
	after_write_ibject_contents invocation.
	(elfobj_grok_gnu_build_id): Update for new build_id struct.  Don't
	allow zero size notes.
	* configure: Regenerate.
gdb/
	* elfread.c (struct build_id): Delete.  Use struct elf_build_id
	throughout file instead.
	(build_id_bfd_get): Update to use new elf_tdata build_id field.
	Don't xmalloc return value.
	(build_id_verify): Similarly.  Don't xfree.
	(build_id_to_debug_filename): Update.
	(find_separate_debug_file_by_buildid): Update, don't xfree.
ld/
	* emultempl/elf32.em (emit_note_gnu_build_id): New static var.
	Replace all info->emit_note_gnu_build_id refs.
	(id_note_section_size): Rename from
	gld${EMULATION_NAME}_id_note_section_size.
	(struct build_id_info): Delete.
	(write_build_id): Rename from
	gld${EMULATION_NAME}_write_build_id_section.
	Update elf_tdata usage.  Style, formatting.
	(setup_build_id): New function.
	(gld${EMULATION_NAME}_after_open): Use setup_build_id.