Erasure of intersection types doesn't follow the specification

[hamzaremmal]

Compiler version

3.x.y

Minimized code

trait Bar

object Foo:
  val x: Bar & Object = ???
  def foo(s: Bar & Object) = ???

Output

If we inspect with -Xprint:genBCode on Scala 3.0.0.

package <empty> {
  @scala.annotation.internal.SourceFile("test.scala") trait Bar() extends Object
     {
  }
  @scala.annotation.internal.SourceFile("test.scala") final module class Foo$
     extends
   Object {
    def <init>(): Unit = 
      {
        super()
        Foo$#x = ???()
        ()
      }
    private def writeReplace(): Object = 
      new scala.runtime.ModuleSerializationProxy(classOf[Foo$])
    private <static> val x: Object
    def x(): Object = Foo$#x
    def foo(s: Object): Nothing = ???()
  }
  final lazy module val Foo: Foo$ = new Foo$()
}

Expectation

Bar & Object should erase to Bar (not Object) since Bar <: Object when we compute the eglb(erased(Bar), erased(Object)) ==> eglb(Bar, Object) ==> Bar

Notes

Note that since this is an erasure bug, there is nothing we can do for it in Scala 3 (hence labeling it with wontfix). It is added to the backlog to remember it existence in an eventual situation where we can fix it.