https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110124
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- So basically more code for the C++20 case causes the less inlining into main. Overall this is not an bug really because GCC treats main as known to be called only once and anything main calls is not always inlined as much as what would happen into other functions.
