[Bug d/91628] libdruntime uses glibc internal symbol on s390

[fw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91628

--- Comment #4 from Florian Weimer <fw at gcc dot gnu.org> ---
(In reply to Iain Buclaw from comment #3)
> The use of the function is for the garbage collector to be able to scan
> native TLS data.
> 
> The logic of said function pretty much matches what the glibc macro
> __TLS_GET_ADDR is doing.

But you can use __tls_get_addr on other architectures, right?

I think for s390 and s390x, you should implement you own version of
__tls_get_addr (under a different/hidden name, of course) which is based on
__tls_get_offset, which is the official interface for this.