[patch]: Add check for stdint header

[Ralf Wildenhues]

* Richard Guenther wrote on Fri, Sep 04, 2009 at 11:57:23AM CEST:
> I suppose the explicit check for stdint.h is not necessary and you need to
> cover for the case where inttypes.h provides the required definition.  See
> the autoconf manual which says
> 
>  -- Macro: AC_TYPE_INTPTR_T
>      If `stdint.h' or `inttypes.h' defines the type `intptr_t', define
>      `HAVE_INTPTR_T'.  Otherwise, define `intptr_t' to a signed integer
>      type wide enough to hold a pointer, if such a type exists.
> 
> I don't know what the canonical header inclusion case to use would be
> though.  Maybe Ralf knows.

FWIW (since I've been asked by name here) I can't see obvious issues
with the patches in this thread, but also, the GCC build system
maintainers know much better what is needed for GCC here than I do.

Using AC_TYPE_INTPTR_T outside of GCC, you'd include both inttypes.h
and stdint.h, if they are available; that's what the test does, too.

Cheers,
Ralf