[path-fixed] Distinguish cw and ccw boxes

To correctly handle retessellating trapezods constructed from alternately
wound boxes, then we need to pass that information from the path to the
tessellator. We do this by switching the direction of the box if the first
edge is horizontal as opposed to vertical.

src/cairo-path-fixed.c

@@ -1300,8 +1300,8 @@ _cairo_path_fixed_iter_is_fill_box (cairo_path_fixed_iter_t *_iter,
 	points[2].x == points[3].x &&
 	points[3].y == points[0].y)
     {
-	box->p1 = points[0];
-	box->p2 = points[2];
+	box->p1 = points[1];
+	box->p2 = points[3];
 	*_iter = iter;
 	return TRUE;
     }