[PATCH] elf: Add __libc_get_static_tls_bounds [BZ #16291]

[Florian Weimer]

* Joseph Myers:

> On Fri, 24 Sep 2021, Fangrui Song via Libc-alpha wrote:
>
>> This patch implements __libc_get_static_tls_bounds@@GLIBC_PRIVATE which
>> is available in Android bionic since API level 31. This API allows the
>> sanitizer code to be more robust. _dl_get_tls_static_info@@GLIBC_PRIVATE
>> can probably be removed when Clang/GCC sanitizers drop reliance on it.
>> I am unclear whether the version should be GLIBC_2.*.
>
> Any interface intended to be used outside of code distributed with glibc 
> should use a symbol version GLIBC_2.* not GLIBC_PRIVATE.

This interface will not be supportable indefinitely, though.  It's still
extremely tied to glibc implementation details.  So making it a public
symbol doesn't seem the right choice at this point.

Thanks,
Florian