[Bug libstdc++/91067] [9/10 Regression] Clang compiler can't link executable if std::filesystem::directory_iterator is encountered

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91067

--- Comment #16 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Except -O0, which is what I find surprising.