A Newlib including the following patch is required:
2013-04-25 Sebastian Huber <sebastian.huber@embedded-brains.de>
* libc/stdio/local.h (_STDIO_CLOSE_PER_REENT_STD_STREAMS): New define.
* libc/stdio/findfp.c (_STDIO_CLOSE_PER_REENT_STD_STREAMS): Use define.