* elf64-ppc.c: Remove stale part of ABI comment.

	* elf64-ppc.c: Remove stale part of ABI comment.
	(NO_OPD_RELOCS): Define.
	(ppc64_elf_check_relocs): Use it.
	(ppc64_elf_relocate_section): Here too.
	(build_one_stub): Don't point function syms at the stub.  Instead,
	hijack plt.offset.
	(ppc64_elf_relocate_section): Check whether REL24 relocs should
	really go to the stub.  Make all dynamic relocs in opd against
	locals.
	(ppc64_elf_finish_dynamic_symbol): Allow for non-standard use of
	plt.offset.