Diagnostic `error[E0408]: variable ... is not bound in all patterns` should be more helpful with typos.

[vi]

Example:

enum Lol {
    Foo,
    Bar,
}

fn foo(x: (Lol,Lol)) {
    use Lol::*;
    match x {
        (Foo,Bar)|(Ban,Foo) => {}
        _ => {}
    }
}

fn main() {
    use Lol::*;
    foo((Foo,Bar));
}

error[E0408]: variable `Ban` is not bound in all patterns
 --> src/main.rs:9:9
  |
9 |         (Foo,Bar)|(Ban,Foo) => {}
  |         ^^^^^^^^^  --- variable not in all patterns
  |         |
  |         pattern doesn't bind `Ban`

I want it to detect atypical upper-cased variable and trigger search for of enum variants with small edit distance. The notice about the type may be even shown before the actual error message itself to avoid missing it.

[estebank]

Current output:

error[E0408]: variable `Ban` is not bound in all patterns
 --> src/main.rs:9:9
  |
9 |         (Foo,Bar)|(Ban,Foo) => {}
  |         ^^^^^^^^^  --- variable not in all patterns
  |         |
  |         pattern doesn't bind `Ban`
  |
help: if you meant to match on a variant or a `const` item, consider making the path in the pattern qualified: `path::to::ModOrType::Ban`
 --> src/main.rs:9:20
  |
9 |         (Foo,Bar)|(Ban,Foo) => {}
  |                    ^^^