[llvm] [LLVM][IR] Add native vector support to ConstantInt & ConstantFP. (PR #74502)

[Paul Walker via llvm-commits]

paulwalker-arm wrote:

Hi @nikic, I had to put this on the back burner but I'm back now.  I believe the rebase last year was the completion point for this stage of the work so the patch should be good to review.  Given the time though I'll rebase and retest tomorrow but wanted to check if your assessment matches mine or whether you feel more is needed?

Separately to this I will create some NFC patches to port tests to the newer splat syntax so I can more easily find the failure paths when enabling the new functionality.

https://github.com/llvm/llvm-project/pull/74502