[llvm] [AArch64][SVE] Use SVE for scalar FP converts in streaming[-compatible] functions (1/n) (PR #118505)

[Paul Walker via llvm-commits]

https://github.com/paulwalker-arm commented:

I'm worried the common case will be either no improvement or worse because there is still a GPR-FPR transfer somewhere in the DAG (as demonstrated by the unit tests) or some other hazard.  

That said, as the combine is limited to streaming[-compatible] functions I'm happy to see how the functionality matures.

https://github.com/llvm/llvm-project/pull/118505