fn f() {
    unsafe {
        goto f1 // forward
        goto f2
        f1:
        goto a1
        _ = fn () {
            goto f1 // the `f1` label is not available here; it is in the outer scope
            goto f2 // same with `f2`
            goto a1 // this is ok
            a1:
            goto a1
        }
        f2:
        goto a1
        goto f1 // back
        goto f2
    }
}

fn g() {
    unsafe {
        goto g1 // forward
        g1:
        goto f1
        goto a1
        goto g1 // back
        goto undefined
    }
}

// implicit main
unsafe {
    goto m1
    m1:
    goto m1
}