This reverts commit 897d8ee5cd693e17f95a7e84194bca4c089a520b, due to causing an infinite loop when encountering a loop with a sub-region with an inner loop.
This reverts commit 897d8ee5cd693e17f95a7e84194bca4c089a520b, due to causing an infinite loop when encountering a loop with a sub-region with an inner loop.