[llvm] [LSR] Deduplicate cast instructions across ICmpZero fixups (PR #201970)

[Nikita Popov via llvm-commits]

nikic wrote:

Sorry, what I meant is not for the reduced test case in this patch (for which, imho, this is the not the best solution), but for the original sealcrypto test case.

https://github.com/llvm/llvm-project/pull/201970