update swig on windows

winx64/bin/swigwin-4.0.0/Examples/contract/simple_c/example.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+int Circle (int x, int y, int radius) {
+  /* Draw Circle */
+  printf("Drawing the circle...\n");
+  /* Return -1 to test contract post assertion */
+  if (radius == 2)
+    return -1;
+  else
+    return 1;
+}