[llvm] [AArch64][SVE] Lower scalar FP converts to SVE when Neon is unavailable (PR #112564)

[Paul Walker via llvm-commits]

paulwalker-arm wrote:

To clarify my previous comment.  I'm not suggesting you "must" implement a set of `fp_op->gpr->fpr` combines specific to the sequences you care about.  I only used that to illustrate my view of this being a combine rather than a lowering problem.  If splitting the operation in two (i.e. in_place_fp_cvt->transfer_to_gpr) is sufficient for your needs (because there are already combines that'll remove transfer_to_gpr) then I'm happy with that.

https://github.com/llvm/llvm-project/pull/112564