[clang] [llvm] [openmp] [Clang][OpenMP] Add `#pragma omp flatten` loop directive + `depth` clause (PR #206977)

[Michael Kruse via cfe-commits]

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@@ -16382,6 +16395,277 @@ StmtResult SemaOpenMP::ActOnOpenMPInterchangeDirective(
                                          buildPreInits(Context, PreInits));
 }
 
+/// Counts the perfectly nested canonical loop depth at \p AStmt. Returns
+/// std::nullopt if a loop-generating transformation prevents a static count.
+static std::optional<unsigned> getCanonicalLoopNestDepth(Stmt *AStmt) {
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Meinersbur wrote:

Please try to use existing functions. If you cannot adapt `doForAllLoops`, at least use `OMPLoopBasedDirective::tryToFindNextInnerLoop`.

https://github.com/llvm/llvm-project/pull/206977