Give better error when matching too many fields

[LPTK]

I just spent a good amount of time trying to figure out why my code would not compile after a refactoring, because the error message was inadequate.

Minimized example

case class Var(name: String)

@main def f = Var("a") match
  case Var(name, _) => name: String

Output

Found:    (name : Any)
Required: String

Expectation

Too many patterns given in `Var`

[dwijnand]

Scala 2 says:

Var.scala:5: error: wrong number of arguments for pattern Var(name: String)
    case Var(name, _) => name: String
            ^
1 error