[clang] [Clang][OpenMP][LoopTransformations] Fix incorrect number of generated loops for Tile and Reverse directives (PR #140532)

[Michael Kruse via cfe-commits]

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

I am OK with this patch as-is, independented of #139293 since it was cleary a (my) mistake. Just a test case to detect regressions would be nice if possible.

So I LGTM this patch. If @alexey-bataev wants additional changes, this can be done independently.

https://github.com/llvm/llvm-project/pull/140532