[llvm] [AArch64] Expand vector ops when NEON and SVE are unavailable. (PR #90833)

[Sander de Smalen via llvm-commits]

sdesmalen-arm wrote:

This PR is currently still based off #90723 but I'll rebase once that PR lands.

The patch to review is: https://github.com/llvm/llvm-project/pull/90833/commits/2270ec14ae56733c0b65064c109f2ece6215829f

https://github.com/llvm/llvm-project/pull/90833