[llvm] [LAA] Be more careful when evaluating AddRecs at symbolic max BTC. (PR #128061)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

Very confused about the code, although the tests seem to check out. BackedgeTakenInfo has an `IsComplete` indicating whether `SCEVCouldNotCompute` will be returned.

https://github.com/llvm/llvm-project/pull/128061