[llvm] [SCEV] Use context sensative reasoning in howFarToZero (PR #94525)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

This one does have some overhead: https://llvm-compile-time-tracker.com/compare.php?from=21711f89b9d85028160611f725bd33d7832d1d46&to=d89246df52708a8fd1fb126526f104ac89240fef&stat=instructions:u

It would be better to use applyLoopGuards, which should be cheaper and also provide better results for the queries you are performing here.

https://github.com/llvm/llvm-project/pull/94525