[llvm] MachineFunctionPass: Clear properties before running function (PR #67962)

[Matthias Braun via llvm-commits]

MatzeB wrote:

I think complained when we introduced `MachineFunctionPass::getClearedProperties()` / `setProperties()` that we should not have that function and rather clear things within `MachineFunction::runOnMachineFunction` at the apropriate time (but I think I was overruled in review).

I feel slightly uneasy that moving the clearing to before the function will just result in different problems for other passes.

Though pragmatically if we cannot get consensus to remove `getClearedProperties()` and `getSetProperties` APIs in their current form and you can make the tests pass then may as well go for it...

https://github.com/llvm/llvm-project/pull/67962