Degrade Thread.countStackFrames() to throw UOE

This method is deprecated for removal:

@Deprecated(since="1.2", forRemoval=true) int java.lang.Thread.countStackFrames()

Update: This issue was originally created to remove this method. Joe Darcy has suggested that we degrade it first, to throw UOE, in advance of removing it. This is the approach we also used for Thread.stop(Throwable).