Multiple errors on single typo in match pattern

[estebank]

With a single typo in a match arm, we generate three separate errors:

error[E0425]: cannot find value `func` in this scope
   --> 
    |
125 |       Target::Match { ref attr, ref fung} => func.apply(&value, &attr.value)?,
    |                                              ^^^^ did you mean `fung`?

error[E0026]: variant `internal::Target::Match` does not have a field named `fung`
   -->
    |
125 |       Target::Match { ref attr, ref fung} => func.apply(&value, &attr.value)?,
    |                                 ^^^^^^^^ variant `internal::Target::Match` does not have this field

error[E0027]: pattern does not mention field `func`
   -->
    |
125 |       Target::Match { ref attr, ref fung} => func.apply(&value, &attr.value)?,
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing field `func`

We should collect all these errors into a single diagnostic:

error[E0026]: variant `internal::Target::Match` does not have a field named `fung`
   -->
    |
125 |       Target::Match { ref attr, ref fung} => func.apply(&value, &attr.value)?,
    |                                 ^^^^^^^^
    |                                 |
    |                                 variant `internal::Target::Match` does not have this field
    |                                 help: did you mean: `func`

[PramodBisht]

@estebank could you share sample code to exactly reproduce above diagnostic?

[estebank]

enum A {
  A {
    foo: usize,
  }
}

fn main() {
  let x = A::A { foo: 3 };
  match x {
    A::A { fob } => { println!("{}", fob); }
  }
}

[PramodBisht]

I will raise another PR to address the case where we are unnecessarily throwing E0425.