[PATCH] aarch64: Improve codegen in AdvSIMD pow

[Wilco Dijkstra]

Hi Pierre,

> Remove spurious ADRP.
> Improve memory access by shuffling constants and
> using more indexed MLAs.
> 
> A few more optimisation with no impact on accuracy
> - force fmas contraction
> - switch from shift-aided rint to rint instruction
>
> Between 1 and 5% throughput improvement on Neoverse
> V1 depending on benchmark.
> ---
> OK for master? If so please commit for as I don't have commit rights.

OK. Pushed.

Cheers,
Wilco