Support R_PPC64_ADDR64_LOCAL

This adds support for "func@localentry", an expression that returns the
ELFv2 local entry point address of function "func".  I've excluded
dynamic relocation support because that obviously would require glibc
changes.

include/elf/
	* ppc64.h (R_PPC64_REL24_NOTOC, R_PPC64_ADDR64_LOCAL): Define.
bfd/
	* elf64-ppc.c (ppc64_elf_howto_raw): Add R_PPC64_ADDR64_LOCAL entry.
	(ppc64_elf_reloc_type_lookup): Support R_PPC64_ADDR64_LOCAL.
	(ppc64_elf_check_relocs): Likewise.
	(ppc64_elf_relocate_section): Likewise.
	* Add BFD_RELOC_PPC64_ADDR64_LOCAL.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
gas/
	* config/tc-ppc.c (ppc_elf_suffix): Support @localentry.
	(md_apply_fix): Support R_PPC64_ADDR64_LOCAL.
ld/testsuite/
	* ld-powerpc/elfv2-2a.s, ld-powerpc/elfv2-2b.s: New files.
	* ld-powerpc/elfv2-2exe.d, ld-powerpc/elfv2-2so.d: New files.
	* ld-powerpc/powerpc.exp: Run new test.
elfcpp/
	* powerpc.h (R_PPC64_REL24_NOTOC, R_PPC64_ADDR64_LOCAL): Define.
gold/
	* powerpc.cc (Target_powerpc::Scan::local, global): Support
	R_PPC64_ADDR64_LOCAL.
	(Target_powerpc::Relocate::relocate): Likewise.