[llvm] [ScalarEvolutionExpander] Don't drop nowrap flags on addrec expansion (PR #78199)

[Nikita Popov via llvm-commits]

nikic wrote:

I'm not sure where exactly we expand addrecs in canonical mode, so I'd suggest adding an assert into the branch and seeing which tests fail, then modify those.

https://github.com/llvm/llvm-project/pull/78199