inconsistency in pattern matching between Idents and Selects after changes to stabilty/volatility in subtyping

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trait Universe {
  type Name >: Null <: AnyRef with NameApi
  trait NameApi

  type TermName >: Null <: TermNameApi with Name
  trait TermNameApi extends NameApi
}

object Test extends App {
  val u: Universe = ???
  import u._

  locally {
    val ScalaName: TermName = ???
    ??? match {
      case ScalaName => ???
    }
  }
}

t8300-patmat.scala:17: error: stable identifier required, but ScalaName found.
 Note that value ScalaName is not stable because its type, Test.u.TermName, is volatile.
      case ScalaName => ???
           ^
one error found

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Imported From: https://issues.scala-lang.org/browse/SI-8304?orig=1
Reporter: @xeno-by
Affected Versions: 2.11.0-M3

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@adriaanm said:
It's been a while, but I thought we had fixed this. I'll at least see about diagnosing it this week.

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@retronym said:
I've just pushed a commit to scala/scala#3545 which I believe corrects the oversight in #6815.

This example actually didn't compile underl 2.10.3, so I'm removing "regression" from the title. But we shouldn't ship with the inconsistency between Selects and Idents.

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@xeno-by said:
I am sorry for labelling this as a regression. I guess I was using the old version of this test (without locally) to check whether it works for 2.10.4-SNAPSHOT.

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@retronym said:
No matter, a good catch is a good catch!