final implicit class can be overridden

[soronpo]

Overriding a final implicit class's equivalent definition shouldn't be possible.

  trait Foo
  trait Implicits {
    final implicit class FooExtender(foo : Foo) {
      def empty : Unit = {}
    }
  }

  object Test extends Implicits {
    override implicit def FooExtender(foo: Foo): Test.FooExtender = super.FooExtender(foo) //should not be allowed
  }

Same issue in dotty scala/scala3#4948

[lrytz]

scala/scala#7412