[Bug libstdc++/99058] Consider adding a note about std::optional ABI break to the C++17 status table

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99058

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Brad Spencer from comment #0)
> Perhaps I was misusing this table, but I interpreted "supported since 7.1"
> to mean that if I compile against 7.1 headers, my code will remain ABI
> compatible against future versions of the library _and_ other code compiled
> against future versions of the headers.

Absolutely not.