Is Trampoline for Tail Calls Supported in Scala 2.8 and/or Scala 2.9?

http://www.scala-lang.org/api/current/index.html#scala.util.control.TailCalls$

On Mon, May 30, 2011 at 21:10, Sava wrote:
> Dean Wamper and Alex Payne said in "Programming Scala" that support
> for "Trampoline  for Tail Calls" optimization had been planned for
> Scala 2.8. I failed to find info about that on www.scala-lang.org.
> Could somebody point me to right URL/document about that? Thanks in
> advance.
>
> P.S.
> Please forgive me if it was a question for Scala-user group instead.