`minusNameSet`
mkNameSet (hsLTyVarNames tvs)
get (HsDocTy ty _) = getl ty
+ get (HsCoreTy {}) = emptyNameSet -- This probably isn't quite right
+ -- but I don't think it matters
extractHsTyNames_s :: [LHsType Name] -> NameSet
extractHsTyNames_s tys = foldr (unionNameSets . extractHsTyNames) emptyNameSet tys