PR/25259: configure macro to make a stdint.h file

[Paolo Bonzini]

>It turns out that IRIX uses "short" for int_fast16_t, and "unsigned
>short" for uint_fast16_t, which the new gstdint.h always redefine to
>be "int" and "unsigned int" respectively.
>
>I suspect the fix is simply to add a sizeof() test to the configure
>machinery that attempts to determine what the generated gstdint.h
>should look like.
>  
>
Since the generated stdint.h file is not complete anyway (as far as the 
C99 standard mandates) I think a simpler solution is to just delete the 
definition of the fast/least types.  Can you do it?

Paolo