https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112282
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #5)
> But doing intializing au allows it work. that is:
> struct b au = {};
But I put a `__builtin_trap();` any place where au might be used as
uninitalized, and we don't reach those section of code. So ....
