PowerPC64 --no-pcrel-optimize

PowerPC64 --no-pcrel-optimize

This new option effectively ignores R_PPC64_PCREL_OPT, disabling the
optimization of instructions marked by that relocation.  The patch
also disables GOT indirect to GOT/TOC pointer relative code editing
when --no-toc-optimize.

bfd/
	* elf64-ppc.h (struct ppc64_elf_params): Add no_pcrel_opt.
	* elf64-ppc.c (ppc64_elf_relocate_section): Disable GOT reloc
	optimizations when --no-toc-optimize.  Disable R_PPC64_PCREL_OPT
	optimization when --no-pcrel-optimize.
ld/
	* emultempl/ppc64elf.em (params): Init new field.
	(enum ppc64_opt): Add OPTION_NO_PCREL_OPT.
	(PARSE_AND_LIST_LONGOPTS, PARSE_AND_LIST_OPTIONS),
	(PARSE_AND_LIST_ARGS_CASES): Support --no-pcrel-optimize.

(cherry picked from commit 6738c8a7c93cd77a0caa720c6cc21c422561be2c)