Rollup merge of #84818 - ABouttefeux:enum-suggest, r=jackh726

suggestion for unit enum variant when matched with a patern

resolve #84700

add suggestion for code like
```rust
enum FarmAnimal {
    Worm,
    Cow,
    Bull,
    Chicken { num_eggs: usize },
    Dog (String),
}

fn what_does_the_animal_say(animal: &FarmAnimal) {

    let noise = match animal {
        FarmAnimal::Cow(_) => "moo".to_string(),
        _ => todo!()
    };

    println!("{:?} says: {:?}", animal, noise);
}
```

```
error[E0532]: expected tuple struct or tuple variant, found unit variant `FarmAnimal::Cow`
  --> $DIR/issue-84700.rs:15:9
   |
LL |     Cow,
   |     --- `FarmAnimal::Cow` defined here
...
LL |         FarmAnimal::Cow(_) => "moo".to_string(),
   |         ^^^^^^^^^^^^^^^^^^ help: use this syntax instead: `FarmAnimal::Cow`
   ```

0 files changed, 0 insertions, 0 deletions