[llvm] [DAG][X86] Avoid slow masked-store folds on Zen (PR #214187)

[Simon Pilgrim via llvm-commits]

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

 please can you update the summary to reflect the latest patch - you're not adding a new hook anymore, just using isTypeDesirableForOp

https://github.com/llvm/llvm-project/pull/214187