REPL: importing an annotation does not seem to bring it in scope

[smarter]

This might be the same bug as #2109, I'm not sure:

scala> import scala.annotation.unspecialized 
import scala.annotation.unspecialized
scala> class Foo[@unspecialized T] 
-- [E006] Unbound Identifier Error: <console>:4:11 -----------------------------
4 |class Foo[@unspecialized T]
  |           ^^^^^^^^^^^^^
  |           not found: type unspecialized

longer explanation available when compiling with `-explain`
scala> class Foo[@scala.annotation.unspecialized T] 
defined class Foo