[Bug libstdc++/88681] Missing symbol exports in libstdc++.so

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88681

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
N.B. When optimization is enabled the functions are inlined, so the exports
aren't needed.