fix cubic linear test

Check to see if the line between end points is
degenerate before measuring control points.

Also, add test case for a bug to see if it
shows up on any platform.

TBR=reed@google.com
BUG=skia:5169, skia:5240
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2375053002

Review-Url: https://codereview.chromium.org/2375053002
diff --git a/tests/PathOpsSimplifyFailTest.cpp b/tests/PathOpsSimplifyFailTest.cpp
index 359b125..fa168d9 100644
--- a/tests/PathOpsSimplifyFailTest.cpp
+++ b/tests/PathOpsSimplifyFailTest.cpp
@@ -87,10 +87,8 @@
     SkPath result;
     result.setFillType(SkPath::kWinding_FillType);
     bool success = Simplify(path, &result);
-    if (index != 17 && index != 31 && index != 38) {  // cubic fails to chop in two without creating NaNs
-        REPORTER_ASSERT(reporter, success);
-        REPORTER_ASSERT(reporter, result.getFillType() != SkPath::kWinding_FillType);
-    }
+    REPORTER_ASSERT(reporter, success);
+    REPORTER_ASSERT(reporter, result.getFillType() != SkPath::kWinding_FillType);
     reporter->bumpTestCount();
 }