[Bug libstdc++/108490] circle compiler support for libstdc++

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108490

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Yes. The attribute has to be there, so it's a Circle bug if it doesn't support
that grammar.