[AArch64] Add SVE condition codes

[Nick Clifton]

Hi Richard,

> Ah, sorry, I only tested the patch on top of the main SVE series.
> The include then comes from patch 23/32.

Fair enough - I should have thought of that.

Testing the patch also reveals two regressions in the linker testsuite,
but I am going to assume that they are resolved by the main SVE series
as well.

Please consider the SVE condition codes patch approved once the main
series is in.

Cheers
  Nick