Fill struct field with `todo!` never type.

I tried action `Fill struct field` in the following:
```rs
struct A {
    u: f64,
    v: i64,
}

fn f() -> A {
    let u = 5.0;
    let v = todo!();
    A{} // <- @action Fill struct fields.
}
```
And this happened:
```rs
A { u, v: todo!() }
```
Since (IMU) `!` subtypes anything, then I would find it legit that this happened instead:
```rs
A { u, v }
```
What do you think?