[PATCH] D48974: [DomTreeUpdater] Ignore updates when both DT and PDT are nullptrs

[Brian Rzycki via Phabricator via llvm-commits]

brzycki added a comment.

@NutshellySima I think you said that `BasicBlock`s that are deleted with `deleteBB()` aren't removed immediately and are held until a a `flush()` event, correct? I don't see any comments informing the users that this is the case. I consider it to be unexpected behavior and should be noted.

Code-wise it LGTM as well.


https://reviews.llvm.org/D48974