//# run
main() {
    let x: u64;
    let y: u64;
label b0:
    jump_if (true) b2;
label b1:
    x = 42;
    jump b3;
label b2:
    y = 0;
label b3:
    // invalid copy
    assert(copy(y) == 0, 42);
    return;
}