[llvm] [LV] Reland "Add costs for VPInstructionWithType::computeCost" (PR #202952)

[Florian Hahn via llvm-commits]

https://github.com/fhahn approved this pull request.

LGTM, thanks

> Ah ok. I'd better wait a day or two before landing this PR then because the original version of https://github.com/llvm/llvm-project/commit/054a840e0370704c9a9705f5660861f0364d08d8 caused buildbot failures. It would be a mess if that got reverted again with these changes added on top.

I think it should be fine now, but would be good to rebase to re-trigger checks before merge and update the commit message

https://github.com/llvm/llvm-project/pull/202952