INT: splineEdge: allowing usage in extrudeMesh. See #1983.

tutorials/mesh/extrudeMesh/polyline/system/extrudeMeshDict

@@ -42,7 +42,9 @@ polylineCoeffs
         ( 1.5 -1 1.183974596 )
     );
 
-    edges 9
+#if ${USE_ARC:-true}
+    //- Using arcs
+    edges
     (
         line 0 1
         arc  1 2 ( 0 -0.087867966 0.962132034 )
@@ -54,6 +56,22 @@ polylineCoeffs
         arc  7 8 ( 0.976794919 -1 2.009807621 )
         line 8 9
     );
+#else
+    //- Using spline (different shape):
+    edges
+    (
+        spline 0 9
+        (
+            ( 0 0 0.05 )
+            ( 0 0 0.5 )
+            ( 0.5 0  0.5 )
+            ( 0.5 0  0 )
+            ( 1.5 0  0 )
+            ( 1.5 -1 0 )
+            ( 1.5 -1 1.183974596 )
+        )
+    );
+#endif
 
     toleranceCheck  1e-6;
 }