https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107041
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- If this is really just because it is a builtin, I think another possibility would be make it BT_FN_INT_VAR instead of BT_FN_INT_INT and verify it has just one argument which is either int or the particularly named enum say in builtins.cc folding or so.
