Accuracy tests fail in CI on `Ubuntu 20.04`

[flba-eb]

Currently, CI builds fail on Ubuntu 20.04 because a function is not found.

Error message:

thread 'doit' panicked at 'failed to find tests/accuracy/main.rs:63', tests/accuracy/main.rs:106:25

Source code:

#[inline(never)]
#[rustfmt::skip]
fn inner(main_pos: Pos, outer_pos: Pos) {
    check!(main_pos, outer_pos);
    check!(main_pos, outer_pos);
    let inner_pos = pos!(); auxiliary::callback(|aux_pos| { //<--- this is found ✓
        check!(main_pos, outer_pos, inner_pos, aux_pos);
    });
    let inner_pos = pos!(); auxiliary::callback_inlined(|aux_pos| { // [line 63] <--- this is missing ✘
        check!(main_pos, outer_pos, inner_pos, aux_pos);
    });
}

[workingjubilee]

CI is all-green now, so we can close this!