[llvm] [LoopInterchange] Enable it by default (PR #124911)

[Nikita Popov via llvm-commits]

https://github.com/nikic requested changes to this pull request.

As it has been pointed out to me that the current state here isn't very clear: Enablement of LoopInterchange is currently blocked on correctness issues in DependenceAnalysis, mostly related to failure to handle integer overflows.

https://github.com/llvm/llvm-project/pull/124911