[patch config]: Activate POSIX printf/scanf by default for w64 based toolchain

[Jonathan Wakely]

On 22 December 2011 19:14, Kai Tietz wrote:
>
> 2011-12-22  Kai Tietz  <ktietz@redhat.com>
>
>        * config/os/mingw32-w64/os_defines.h (__USE_MINGW_ANSI_STDIO): Define.
>
> Tested for x86_64-w64-mingw32, and i686-w64-mingw32.  Mingw.org's
> variant is unaffected by this patch.
> Ok for apply?

OK