* elf64-ppc.c (ppc64_elf_edit_opd): Support 16 byte long .opd

	* elf64-ppc.c (ppc64_elf_edit_opd): Support 16 byte long .opd
	entries (where fd_aux overlaps next entry's fd_func).
	Add non_overlapping argument, use it.
	(ppc64_elf_check_relocs, ppc64_elf_gc_mark_hook, adjust_opd_syms,
	ppc64_elf_size_stubs, ppc64_elf_relocate_section,
	ppc64_elf_output_symbol_hook): Use address / 8 instead of address / 24
	as indexes into opd_sym_map/opd_adjust array.
	* elf64-ppc.h (ppc64_elf_edit_opd): Adjust prototype.

	* emultempl/ppc64elf.em (non_overlapping_opd): New variable.
	(ppc_before_allocation): Pass it to ppc64_elf_edit_opd).
	(OPTION_NON_OVERLAPPING_OPD): Define.
	(PARSE_AND_LIST_OPTIONS, PARSE_AND_LIST_ARGS_CASES): Add
	--non-overlapping-opd option.