[llvm] [unroll-and-jam] Document dependency patterns in dependencies.ll (NFC) (PR #156577)

[Michael Kruse via llvm-commits]

https://github.com/Meinersbur approved this pull request.

LGTM

Since you alreadt reverse-engineered the functions, pseudocode for the loop nests would have been nice, but adding an analysis is already very helpful.

https://github.com/llvm/llvm-project/pull/156577