needsCDecl :: CLabel -> Bool
  -- False <=> it's pre-declared; don't bother
  -- don't bother declaring Bitmap labels, we always make sure
  -- they are defined before use.
needsCDecl (SRTLabel _)                 = True
needsCDecl :: CLabel -> Bool
needsCDecl (SRTLabel _)                 = True
needsCDecl (SRTLabel _)                 = True