How can I see in what [Java/Scala?] code does Scala compiler rewrites original Scala-code

Following Scala mailing lists, different people often say: "compiler rewrites this [scala] code into this [java/scala??] code". For example, from one of the latest threads, if Scala sees

class C(i: Int = 4) { ... }

then the compiler rewrites this as (effectively):

class C(i: Int) { ... }
object C {
  def init$default$1: Int = 4
}

How can I find out, what will be the compiler output for my code? Should I decompile the resulting bytecode for that?