[llvm] [TTI][Vectorize] Migrate masked/gather-scatter/strided/expand-compress costing (NFCI) (PR #165532)

[Luke Lau via llvm-commits]

https://github.com/lukel97 commented:

The getMemIntrinsicInstrCost hook is fine by me. But I also wonder if it would be possible to store the Instruction + VariableMask inside `IntrinsicCostAttributes` and reuse getIntrinsicInstCost. Is that difficult to do? Not strongly opinionated on this either way

https://github.com/llvm/llvm-project/pull/165532