[LD][AARCH64]Add TLSDESC support for large memory model.

[LD][AARCH64]Add TLSDESC support for large memory model.

bfd/

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

	* elfnn-aarch64.c (aarch64_tls_transition_without_check):  Add
	relax transitions for TLSDESC_ADD, TLSDESC_LDR, TLSDESC_OFF_G0_NC,
	TLSDESC_OFF_G1.
	(aarch64_tls_transition_without_check): Add relaxation support.
	(aarch64_reloc_got_type): Add support.
	(elfNN_aarch64_final_link_relocate): Likewise.
	(elfNN_aarch64_tls_relax): Likewise.
	(elfNN_aarch64_relocate_section): Likewise.
	(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.

ld/testsuite/

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

	* ld-aarch64/aarch64-elf.exp: Run new test.
	* ld-aarch64/tls-large-desc.d: New.
	* ld-aarch64/tls-large-desc.s: New.
	* ld-aarch64/tls-relax-large-desc-ie.d: New.
	* ld-aarch64/tls-relax-large-desc-ie.s: New.
	* ld-aarch64/tls-relax-large-desc-le.d: New.
	* ld-aarch64/tls-relax-large-desc-le.s: New.