[llvm] [SCEV] Add predicate in SolveLinEq to ensure B is a multiple of A. (PR #108777)

[Florian Hahn via llvm-commits]

fhahn wrote:

There was a genuine reverse-iteration failure due to predicates in ExitLimit and ExitNotTaken were stored in SmallPtrSet. I pushed a fix to store them in SmallVectors, doing de-duplication when constructing ExitLimit: 6022a3a05f951632022c84416209fe6d70d9105c

https://github.com/llvm/llvm-project/pull/108777