[LTP] [PATCH] resource: explicitly define _LARGEFILE64_SOURCE

[Petr Vorel]

Hi Li,

> Fix compilation errors on Alpine Linux (musl) by explicitly defining
> _LARGEFILE64_SOURCE instead of _GNU_SOURCE. This ensures that 64-bit
> resource limit structures (e.g., struct rlimit64) are properly exposed
> in <sys/resource.h>.

> To resolve the compiling error on Alpine:
>   https://github.com/linux-test-project/ltp/actions/runs/13580985467/job/37966850497

I dared to merge to fix the CI.
Thank you for the fix!

Kind regards,
Petr