bfd/

bfd/
	* elf-bfd.h (struct elf_obj_tdata): Delete dt_soname field.  Add
	dyn_lib_class field.  Rearrange for better packing.
	(elf_dt_soname): Delete.
	(elf_dyn_lib_class): Define.
	* elf.c (bfd_elf_set_dt_needed_name): Update comment.
	(bfd_elf_set_dt_needed_soname): Delete.
	(bfd_elf_set_dyn_lib_class): New function.
	* elflink.h (add_dt_needed_tag): New function.  Split out from..
	(elf_link_add_object_symbols): ..here.  Rename "name" to "soname".
	Use elf_dyn_lib_class to set dt_needed and add_needed.  Move fallback
	initialization of soname.
	(elf_link_check_versioned_symbol): Test elf_dyn_lib_class instead of
	elf_dt_soname.
	* bfd-in.h (enum dynamic_lib_link_class): New.
	(bfd_elf_set_dt_needed_soname): Delete.
	(bfd_elf_set_dyn_lib_class): Declare.
	* bfd-in2.h: Regenerate.
ld/
	* ld.texinfo: Add --as-needed doco.
	* ldmain.c (as_needed): New global var.
	* ldmain.h (as_needed): Declare.
	* lexsup.c (option_values): Add OPTION_AS_NEEDED and
	OPTION_NO_AS_NEEDED.
	(ld_options): Likewise.
	(parse_args): Handle them.
	* ldlang.h (lang_input_statement_type): Add as_needed field.
	* ldlang.c (new_afile): Set p->as_needed.
	* emultempl/elf32.em (gld${EMULATION_NAME}_load_symbols): New function.
	(gld${EMULATION_NAME}_try_needed): Use bfd_elf_set_dyn_lib_class.
	(ld_${EMULATION_NAME}_emulation): Set LDEMUL_RECOGNIZED_FILE entry.

	* ldlang.c (open_input_bfds): Remove useless cast.
	(lang_do_assignments_1): Likewise.
	(lang_for_each_input_section): Delete.