Overload resolution falls into inference failures if we rely on return type adaptation with a polymorphic view

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trait Arr[T]
object Arr {
  def apply[T](xs: T): Arr[T]    = null
  def apply(x: Long) : Arr[Long] = null
}

object I {
  implicit def arrToTrav[T] (a: Arr[T])   : Traversable[T]    = null
  implicit def longArrToTrav(a: Arr[Long]): Traversable[Long] = null
}
  
object Test {
  def foo(t: Traversable[Any]) {}

  object Okay {
    Arr("1")

    import I.{ arrToTrav, longArrToTrav }
    foo(Arr("2"))
  }

  object Fail {
    import I.arrToTrav
    foo(Arr("3")) // found String, expected Long
  }
}

Extracted from a bootstrap failure I encountered when messing with error reporting from isCompatble/ viewExists in #8219

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Imported From: https://issues.scala-lang.org/browse/SI-8230?orig=1
Reporter: @retronym
Affected Versions: 2.10.3

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@retronym said:
Pending test and analysis: https://github.com/retronym/scala/compare/ticket/8230