Circular object dependency results in null field

[scabug]

The following code compiles without errors but results in a field unexpectedly being null:

$ scala
Welcome to Scala version 2.11.6 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_40).
scala> :paste
// Entering paste mode (ctrl-D to finish)

sealed abstract class OrderType(val reverse: OrderType)
case object Buy extends OrderType(Sell)
case object Sell extends OrderType(Buy)

// Exiting paste mode, now interpreting.

defined class OrderType
defined object Buy
defined object Sell

scala> Buy.reverse
res0: OrderType = Sell

scala> Sell.reverse
res1: OrderType = null

(May or may not be related to #9115 and/or #5366.)

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-9261?orig=1
Reporter: Mirko Nasato (mnasato)
Affected Versions: 2.11.6
See #5366, #9115