[PATCH v3] Always define __USE_TIME_BITS64 when 64 bit time_t is used

[Florian Weimer]

* Andreas K. Huettel:

> When rebuilding a riscv32 qemu chroot with this patch I get errors similar to
>
> (python)
> ceval.c:(.text+0x272a): undefined reference to `__pthread_cond_timedwait64'
> collect2: error: ld returned 1 exit status
>
> (gnupg)
> /usr/lib/gcc/riscv32-unknown-linux-gnu/13/../../../../riscv32-unknown-linux-gnu/bin/ld: /usr/lib32/ilp32d/libnpth.so: undefined reference to `__pthread_mutex_timedlock64'

This could happen if you build against a mixed of old and new headers.
(Old headers which check __USE_TIME_BITS64, but a new header that
defines __USE_TIME_BITS64 because the architecture has time64.)

Thanks,
Florian