[llvm] LCA: migrate from DA to LAA; fix cost computation (PR #107691)

[Sjoerd Meijer via llvm-commits]

sjoerdmeijer wrote:

And maybe for a little bit more context, we are very much interested in loop-interchange and DependenceAnalysis, which is why I CC'ed Sebastian. We are thinking of trying to get at least one of the loop optimizations that uses DA enabled. We do appreciated that some work is required as there are some issues raised against components (interchange and DA), and we are trying to form an opinion what the work would involve.

https://github.com/llvm/llvm-project/pull/107691