[llvm] Fix issue with running the same PassManager twice (PR #92823)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

> But given `MaxDevirtIterations` is `const` this isn't really a runtime decision. It seems like MIWP can be replaced with a regular MPM and the decision above be made at pipeline construction. Is that the direction you're suggesting?

Yes, exactly

https://github.com/llvm/llvm-project/pull/92823