[llvm] [BBUtils][NFC] Delete SplitLandingPadPredecessors with DT (PR #73406)

[Nikita Popov via llvm-commits]

nikic wrote:

Adding @kuhar here to get an opinion on the general direction. We have a bunch of APIs in BBUtils that support both DT and DTU. The UpdateAnalysisInformation() handles the actual updates using either DT or DTU.

To what degree is it our goal to switch updates directly on DT to use DTU, in places that don't otherwise use DTU? My understanding is that the updates directly on DT will be more efficient than going through the generic DTU implementation, so I'm not really clear on whether this kind of change is desirable or not.

https://github.com/llvm/llvm-project/pull/73406