Correct elf64-ppc.c handling of protected symbols

Correct elf64-ppc.c handling of protected symbols

Some places in elf64-ppc.c carelessly used SYMBOL_CALLS_LOCAL when
the proper test is SYMBOL_REFERENCES_LOCAL for cases where we take the
address of a protected symbol.  This works OK for function descriptors
but not for ELFv2.  Setting symbols to their global entry stub a
little earlier is to ensure _bfd_elf_hash_symbol allows such symbols
in .gnu.hash.

	* elf64-ppc.c (ppc64_elf_edit_toc): Use SYMBOL_REFERENCES_LOCAL
	here, not SYMBOL_CALLS_LOCAL.
	(ppc64_elf_relocate_section): Likewise.
	(size_global_entry_stubs): Set undefined symbols on their global
	entry stubs here..
	(build_global_entry_stubs): ..rather than here.
	(ppc64_elf_build_stubs): Don't reset glink->size before calling
	build_global_entry_stubs.