U = union
{
    s: s32,
    u: u32,
}

[export] main = fn [cc(c)] () s32
{
    >my_union: U = {
        .s = -1,
    };
    if (my_union.s != -1) #trap();
    if (my_union.u != 0xffffffff) #trap();
    return 0;
}