fix pathops skp-derived bugs; add more failing tests

src/pathops/SkOpContour.cpp

Index: src/pathops/SkOpContour.cpp
diff --git a/src/pathops/SkOpContour.cpp b/src/pathops/SkOpContour.cpp
index 5ef702d4c10cb462d66130918090e53ace7467e5..e4dd62a653d3235aea9f623ef7f402c95a59f0ad 100644
--- a/src/pathops/SkOpContour.cpp
+++ b/src/pathops/SkOpContour.cpp
@@ -452,8 +452,14 @@ void SkOpContour::checkCoincidentPair(const SkCoincidence& oneCoin, int oneIdx,
     }
     if (cancelers) {
         if (missingT1 >= 0) {
+            if (addTo1->reversePoints(missingPt1, missingPt2)) {
+                SkTSwap(missingPt1, missingPt2);
+            }
             addTo1->addTCancel(missingPt1, missingPt2, addOther1);
         } else {
+            if (addTo2->reversePoints(missingPt1, missingPt2)) {
+                SkTSwap(missingPt1, missingPt2);
+            }
             addTo2->addTCancel(missingPt1, missingPt2, addOther2);
         }
     } else if (missingT1 >= 0) {