ppc64 section group handling

ppc64 section group handling

Two organizational changes to the array of additional info kept for
sections.
1) Move group info into a per-group allocated struct, in preparation
for future changes that need per-group accounting.
2) Expand the array to include output sections, which simplifies
sizing and removes the need for a separate output section array.

	* section.c (section_id): Make file scope.
	(bfd_get_next_section_id): New function.
	* elf64-ppc.c (struct map_stub): Remove toc_off field.  Move decl.
	(struct ppc_stub_hash_entry): Delete stub_sec and id_sec.  Add
	group.  Update all uses.
	(struct ppc_link_hash_table): Delete top_id, top_index, and
	input_list.  Add sec_info_arr_size.  Rename stub_group to
	sec_info, and make group info indirect.  Update stub_group refs
	throughout file.
	(ppc_add_stub): Don't look for stub_sec on link_sec stub_group
	entry.
	(ppc_build_one_stub): Delete FIXME.
	(ppc64_elf_setup_section_lists): Size htab->sec_info for all
	sections, not just input sections.  Don't create htab->input_list.
	(ppc64_elf_next_input_section): Update to use sec_info union as
	list pointer.
	(PREV_SEC): Delete.
	(group_sections): Pass "info" param rather than "htab".  Iterate
	over output sections rather than input_list.  Use sec_info union
	as list pointers.  Alloc atruct map_stub, and return fail status.
	* bfd-in2.h: Regenerate.