powerpc TLS in PIEs

powerpc TLS in PIEs

This patch removes unnecessary GOT IE TLS relocations in PIEs.  Useful
with --no-tls-optimize, or with an enormous TLS segment.  With the
default --tls-optimize in effect IE code sequences will be edited to
LE under the same circumstances we can remove the GOT reloc.

	* elf32-ppc.c (got_entries_needed, got_relocs_needed): New functions.
	(allocate_dynrelocs, ppc_elf_size_dynamic_sections): Use them here.
	(ppc_elf_relocate_section): Don't output a dynamic relocation
	for IE GOT entries in an executable.
	* elf64-ppc.c (allocate_got): Trim unnecessary TPREL relocs.
	(ppc64_elf_size_dynamic_sections): Likewise.
	(ppc64_elf_relocate_section): Likewise.