PowerPC64 debian bug 886264, out-of-line save/restore functions

PowerPC64 debian bug 886264, out-of-line save/restore functions

This calculation in relocate_section

	      if (stub_entry->stub_type == ppc_stub_save_res)
		relocation += (stub_sec->output_offset
			       + stub_sec->output_section->vma
			       + stub_sec->size - htab->sfpr->size
			       - htab->sfpr->output_offset
			       - htab->sfpr->output_section->vma);

to adjust from the original out-of-line save/restore function address
in sfpr to a copy at the end of stub_sec goes wrong when stub_sec is
padded, because the copy is no longer at the end of stub_sec.  The
solution is to pad before copying sfpr, so the copy is always at the
end of stub_sec.

	* elf64-ppc.c (sfpr_define): Adjust for stub_sec size having
	sfpr size added before defining alias symbols.
	(ppc64_elf_build_stubs): Add stub section padding before
	copying sfpr contents and defining save/restore alias symbols.

(cherry picked from commit 7dda8d3cf3b089bb7e03c4cdbec827fc6a188c88)