Add needed include files for flags needed by open.

src/vio/csync_vio.h

@@ -23,6 +23,10 @@
 #ifndef _CSYNC_VIO_H
 #define _CSYNC_VIO_H
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
 #include "vio/csync_vio_handle.h"
 #include "vio/csync_vio_file_stat.h"