update swig on windows

winx64/bin/swigwin-4.0.0/Examples/ocaml/string_from_ptr/example.i

@@ -0,0 +1,16 @@
+%module example
+%{
+static int foo( char **buf ) {
+  *buf = "string from c";
+  return 0;
+}
+%}
+
+%typemap(in,numinputs=0) char **buf (char *temp) {
+    $1 = &temp;
+}
+%typemap(argout) char **buf {
+    swig_result = caml_list_append(swig_result,caml_val_string((char *)*$1));
+}
+
+int foo( char **buf );