[flang] [llvm] [mlir] [flang][OpenMP] Enable tiling (PR #143715)

[Sergio Afonso via llvm-commits]

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

Thank you Jan again for all the work on this. LGTM, just some non-blocking nits left from me. Feel free to merge when everyone is happy.

https://github.com/llvm/llvm-project/pull/143715