bug#72036: 31.0.50; master doesn't build on macOS with clang 18

[Gerd Möllmann]

Pip Cet <pipcet@protonmail.com> writes:

> (CC'ing Paul Eggert and Jim Meyering, the relevant gnulib maintainers).
>
> On Wednesday, July 10th, 2024 at 14:09, Gerd Möllmann 
> <gerd.moellmann@gmail.com> wrote:
>> master, HEAD a29a385ee5ea938ed17d94622c7bfd0a10e84830
>> 
>> timespec-sub.c:38:12: error: operand argument to checked integer operation 
>> must be an integer type
>> other than plain 'char', 'bool', bit-precise, or an enumeration ('bool' 
>> invalid)
>> 38 | if (v == ckd_sub (&rs, rs, borrow))
>>    |          ^~~~~~~~~~~~~~~~~~~~~~~~~
>> /opt/homebrew/Cellar/llvm/18.1.8/lib/clang/18/include/stdckdint.h:38:54: 
>> note: expanded from macro
>> 'ckd_sub'
>> 38 | #define ckd_sub(R, A, B) __builtin_sub_overflow((A), (B), (R))
>>    |                                                      ^~~
>
> The attached patch to gnulib helps here. I'm using clang version
> 18.1.8 and the testdir-all build fails if I ./configure CC=clang.

Thanks!