[llvm] [InstCombine] Fold `select(load, val) + store` into `llvm.masked.store` (PR #144298)

[Nikita Popov via llvm-commits]

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

This is (extremely!) unprofitable for targets that don't have native masked stores. It will expect to a long chain of conditional stores.

https://github.com/llvm/llvm-project/pull/144298