PATCH libgfortran mmap fixes for MinGW

[Aaron W. LaFramboise]

Paul Brook wrote:

> I changed it to define PROT_* if absent, instead of #ifdefs in the code.
> Applied as below.
> 
> Paul
> 
> 2004-09-15  Aaron W. LaFramboise <aaronavay62@aaronwl.com>
> 
>  * config.h.in: Regenerate.
>  * configure: Regenerate.
>  * configure.ac (AC_CHECK_HEADERS): Check for sys/mman.h.
>  * unix.c: Include stdio.h.
>  (HAVE_SYS_MMAN_H): Check.
>  (PROT_READ, PROT_WRITE): Provide default definitions.

Sorry, I didn't notice at the time, but the <stdio.h> bit got missed.
The STD*_FILENO macros are defined in <stdio.h> in MinGW.

Aaron W. LaFramboise