[PATCH v6] string: Add tests for unique strerror and strsignal strings

[Florian Weimer]

* Arjun Shankar:

> strerror, strsignal, and their variants should return unique strings for
> each known (and, depending on the function, unknown) error/signal.  Add
> tests to verify this for strerror, strerror_r (GNU and XSI compliant
> variants), and strerror_l (for the C locale), strerrordesc_np,
> strsignal, sigabbrev_np, and sigdescr_np.
>
> Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

This version looks good to me.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Maybe wait a day or two to see if Adhemerval has comments?

Thanks,
Florian