[PATCH 3/3][Binutils] aarch64: Add GCS system registers.

[Nick Clifton]

Hi Srinath,

> This patch adds support for 10 new AArch64 system registers
> (gcscre0_el1, gcscr_el1, gcscr_el12, gcscr_el2, gcscr_el3,
> gcspr_el0, gcspr_el1 ,gcspr_el12, gcspr_el2 and gcspr_el3),
> which are enabled on using Guarded Control Stack (+gcs flag)
> feature.
> 
> Regression tested for aarch64-none-elf target and found no regressions.
> 
> Ok for binutils-master?

Approved - please apply.

Cheers
   Nick