[Bug libstdc++/108969] [13/14 Regression] Initializing iostreams in the library needs a GLIBCXX_3.4.31 versioned symbol

[fw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108969

--- Comment #23 from Florian Weimer <fw at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #20)
> So, when the @@GLIBCXX_3.4.31 alias is weak, at least the F36 linker puts
> into the binary not just one but both symbols and so the aliasing isn't
> broken.

I'm not sure this is sufficient because old programs will only have the
@GLIBCXX_3.4 reference and still break the aliases if copy relocations are
involved. The internal libstdc++ things we could perhaps resolve, but even with
that, it will only work if everything in the executable either uses the old
version, or the new version. Mixed-mode operation still won't work because of
the separation of the aliases.