Compiler fails to inline

[allanrenucci]

The following code snippet does not compile with Dotty:

class Set[A] {

  def incl(elem: A): Set[A] = ???

  inline final def + (elem: A): Set[A] = incl(elem)
}

object Set {
  def apply[A](elems: A*): Set[A] = ???
}

class Test {
  Set(1) + 1
}

-- Error: tests/allan/Test.scala:13:9 ------------------------------------------
13 |  Set(1) + 1
   |  ^^^^^^^^^^
   |undefined: Set_this.incl # 191: TermRef(TermRef(NoPrefix,val Set_this),incl[with sig Signature(List(java.lang.Object),Set)])

It compiles without the inline keyword.

[odersky]

Fixed by #3494