[LD][AARCH64]Add BFD_RELOC_AARCH64_LD64_GOTOFF_LO15 Support.

[LD][AARCH64]Add BFD_RELOC_AARCH64_LD64_GOTOFF_LO15 Support.

bfd/

2015-10-02  Renlin Li  <renlin.li@arm.com>

	* elfnn-aarch64.c (aarch64_reloc_got_type): Add
	BFD_RELOC_AARCH64_LD_64_GOTOFF_LO15 support.
	(elfNN_aarch64_gc_sweep_hook): Likewise.
	(elfNN_aarch64_check_relocs): Likewise
	* elfxx-aarch64.c (_bfd_aarch64_elf_put_addend): Likewise.
	(_bfd_aarch64_elf_resolve_relocation): Likewise
	(elfNN_aarch64_final_link_relocate): Calculate offset within GOT.

ld/testsuite/

2015-10-02  Renlin Li  <renlin.li@arm.com>

	* ld-aarch64/emit-relocs-310.d: New.
	* ld-aarch64/emit-relocs-310.s: New.
	* ld-aarch64/aarch64-elf.exp: Run the test.