Patch #734231: Update RiscOS support. In particular, correct
riscospath.extsep, and use os.extsep throughout.
diff --git a/Include/pyport.h b/Include/pyport.h
index b68a3b4..c358cc2 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -147,6 +147,7 @@
 
 #ifdef RISCOS
 #include <sys/types.h>
+#include "unixstuff.h"
 #endif
 
 #ifndef DONT_HAVE_SYS_STAT_H