THREAD_GETMEM support for Hurd in glibc

[Florian Weimer]

* Samuel Thibault:

> Hello,
>
> Florian Weimer, le sam. 15 févr. 2020 11:11:02 +0100, a ecrit:
>> Is there a way to add fields to the thread descriptor on Hurd?
>
> Sure!
>
>> With NPTL, we have THREAD_GETMEM and THREAD_SETMEM to access
>> thread-local variables without relying on the platform TLS
>> implementation.
>
> I have now added them.

Thanks, this is very useful and allowed me to simplify the loader
exception handling.