[GAS][AARCH64]Add BFD_RELOC_AARCH64_LD64_GOTOFF_LO15 Support

[Nicholas Clifton]

Hi Renlin,

> bfd/ChangeLog:
>
> 2015-06-04  Renlin Li <renlin.li@arm.com>
>
>      * reloc.c (BFD_RELOC_AARCH64_LD64_GOTOFF_LO15): New entry.
>      * elfnn-aarch64.c (elfNN_aarch64_howto_table): New entry for
>      BFD_RELOC_AARCH64_LD64_GOTOFF_LO15.
>      * bfd-in2.h: Regenerate.
>      * libbfd.h: Regenerate.
>
> gas/ChangeLog:
>
> 2015-06-04  Renlin Li <renlin.li@arm.com>
>
>      * config/tc-aarch64.c (reloc_table): New relocation modifier.
>      (md_apply_fix): Support BFD_RELOC_AARCH64_LD64_GOTOFF_LO15.
>      (aarch64_force_relocation): Ditto
>
> gas/testsuite/ChangeLog:
>
> 2015-06-04  Renlin Li <renlin.li@arm.com>
>
>      * gas/aarch64/reloc-insn.s: Update test
>      * gas/aarch64/reloc-insn.d: Update expected result.

Approved - please apply.

Cheers
   Nick