https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99137
--- Comment #5 from Tobias Burnus <burnus at gcc dot gnu.org> --- Iff it is decided that it is invalid code, the following patch rejects it: https://gcc.gnu.org/pipermail/gcc-patches/2021-February/565576.html (I forgot to reload the PR before posting.)