[Bug c++/77564] Code fails to link when compiled with -O0

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77564

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I suspect you need a definition of FHT::READ_TIMEOUT, not just a declaration of
it.