update swig on windows

winx64/bin/swigwin-4.0.0/Examples/ruby/value/example.c

@@ -0,0 +1,15 @@
+/* File : example.c */
+
+#include "example.h"
+
+double dot_product(Vector a, Vector b) {
+  return (a.x*b.x + a.y*b.y + a.z*b.z);
+}
+
+Vector vector_add(Vector a, Vector b) {
+  Vector r;
+  r.x = a.x + b.x;
+  r.y = a.y + b.y;
+  r.z = a.z + b.z;
+  return r;
+}