The equality and hash code methods do not work properly for non-empty array builders

[plokhotnyuk]

Compiler version

Both Scala 2.13.x and Scala 3.x are affected

Minimized code

@main def test = {
  println(Array.newBuilder[Int].addOne(1) == Array.newBuilder[Int].addOne(1))
  println(Array.newBuilder[Int].addOne(1).hashCode == Array.newBuilder[Int].addOne(1).hashCode)
}

Output

false
false

Expectation

true
true

Details

The implementations have overridden equals, but in a wrong way, like here for ArrayBuilder.ofInt:

    override def equals(other: Any): Boolean = other match {
      case x: ofInt => (size == x.size) && (elems == x.elems)
      case _ => false
    }

Also, the hashCode implementations are missing.

[som-snytt]

The ancient code was added for a serialization test that tested only an empty builder.