[PATCH] aarch64: Add support for Armv9.1-A to Armv9.3-A

[Nick Clifton]

Hi Richard,

> This patch adds AArch64 support for -march=armv9.[123]-a.
> The behaviour of the new options can be expressed using a
> combination of existing feature flags, so we don't need to
> eat into the vanishing number of spare AARCH64_FEATURE_* bits.
> Hoewver, it was more convenient to separate out the |s of
> feature flags so that Armv9.1-A could reuse the set for
> Armv8.6-A, and so on.
> 
> Tested on aarch64-linux-gnu.  OK to install?

Approved - please apply.

Cheers
   Nick