[llvm] [TTI] Remove masked/gather-scatter/strided/expand-compress costing from TTIImpl (PR #169885)

[Philip Reames via llvm-commits]

https://github.com/preames requested changes to this pull request.

Generally looks correct, a couple small requests for splits, but once done should be approved quickly.  

https://github.com/llvm/llvm-project/pull/169885