[llvm] [SCEV][LV] Invalidate LCSSA exit phis more thoroughly (PR #69909)

[Nikita Popov via llvm-commits]

nikic wrote:

> Yeah probably not necessary. Would still be good to handle AddRecs as well for completeness, even if they may already be invalidated.

Done!

https://github.com/llvm/llvm-project/pull/69909