Add <limits.h> integer width macros

[Florian Weimer]

On 10/04/2016 05:07 PM, Paul Eggert wrote:
> On 09/16/2016 05:32 PM, Paul Eggert wrote:
>> the patch looks good; thanks.
>
> Unfortunately I did not check the patch thoroughly enough, as the patch
> turns out to define LONG_WIDTH incorrectly on i686 with
> gcc-6.2.1-2.fc26.i686, and this causes grep's 'make check' to fail
> (luckily these are side tests; grep itself works fine). See:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=1381582

See comment 5 there.  The problem seems to be that GCC <limits.h> is 
included first, followed by glibc <limits.h>, which then tries to get 
the definitions from GCC.  But at this point, nothing happens because 
the GCC include guards cause the GCC header to be skipped.

The proposed fix doesn't seem right, it would need checks for GCC and 
the GCC version.

Thanks,
Florian