[Mlir-commits] [mlir] [mlir][Interfaces][NFC] Move region loop detection to `RegionBranchOpInterface` (PR #77090)

[Markus Böck]

================
@@ -219,11 +219,21 @@ LogicalResult detail::verifyTypesAlongControlFlowEdges(Operation *op) {
   return success();
 }
 
-/// Return `true` if region `r` is reachable from region `begin` according to
-/// the RegionBranchOpInterface (by taking a branch).
-static bool isRegionReachable(Region *begin, Region *r) {
-  assert(begin->getParentOp() == r->getParentOp() &&
-         "expected that both regions belong to the same op");
+namespace {
+/// Stop condition for `traverseRegionGraph`. The traversal is interrupted if
+/// this function returns "true" for a successor region. The first parameter is
+/// the successor region. The second parameter indicates all already visited
+/// regions.
+using StopConditionFn =
+    std::function<bool(Region *, const SmallVector<bool> &visited)>;
----------------
zero9178 wrote:

```suggestion
    function_ref<bool(Region *, ArrayRef<bool> visited)>;
```

https://github.com/llvm/llvm-project/pull/77090