look for deleted pts when detecting line/curve coincident edges

TBR=reed@google.com
BUG=skia:3651

Review URL: https://codereview.chromium.org/1129863007
diff --git a/src/pathops/SkPathOpsDebug.cpp b/src/pathops/SkPathOpsDebug.cpp
index 2903e08..d28dc72 100644
--- a/src/pathops/SkPathOpsDebug.cpp
+++ b/src/pathops/SkPathOpsDebug.cpp
@@ -364,7 +364,7 @@
         }
         next = next->fNext;
     } while (next && next != first);
-    SkASSERT(wind == 0);
+    SkASSERT(wind == 0 || !FLAGS_runFail);
     SkASSERT(opp == 0 || !FLAGS_runFail);
 #endif
 }