Release 2.40 doesn't build with GCC 15

[Florian Weimer]

* Yury Khrustalev via Libc-help:

> Glibc release release/2.40/master does not build with GCC 15 giving
> multiple errors in timezone/ folder, for example:
>
>   zdump.c:92:66: error: standard ‘reproducible’ attribute can only be
>   applied to function declarators or type specifiers with function type
>      92 | ATTRIBUTE_REPRODUCIBLE static intmax_t delta(struct tm *, struct tm *);
>         |                                                                  ^~
>   zdump.c:92:66: note: did you mean to specify it after ‘)’ following function
>   parameters?
>
> It looks like GCC 15 wants the ATTRIBUTE_REPRODUCIBLE attribute to be
> after function declaration rather than before.
>
> Does this mean that there is maximum GCC version for each Glibc release
> that is supposed to work?

Yes, but historically some of us have backported compatibility patches
to older upstream releases, so it wasn't always very visible.

Thanks,
Florian