[llvm] [InstCombine] Swap out range metadata to range attribute for cttz/ctlz/ctpop (PR #88776)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

Could you please split out the changes to flag clearing into a separate PR? We'll also want to explicitly test them using some call-site of dropPoisonGeneratingFlagsAndMetadata().

And on that note, I don't think this change should be in hasPoisonGeneratingFlags/dropPoisonGeneratingFlags itself, which should stay just about flags. We should handle this in the "AndMetadata" variants -- possibly with a rename of the method, if we want to be pedantic (in the interest of not getting dropPoisonGeneratingFlagsAndMetadataAndAttributes, maybe something like dropPoisonGeneratingAnnotations?). It may make sense to handle the nonnull and align metadata at the same time, if we can come up with some examples of miscompiles for it (maybe something involving ptrmask?)

https://github.com/llvm/llvm-project/pull/88776