message: [FIX] cpp20::views::common with common input
diff: @@ -152,6 +152,13 @@ namespace ranges
  {
  struct cpp20_common_fn
  {
  + template<typename Rng>
  + auto operator()(Rng && rng) const -> CPP_ret(all_t<Rng>)( //
  + requires viewable_range<Rng> && common_range<Rng>)
  + {
  + return all(static_cast<Rng &&>(rng));
  + }
  +
  template<typename Rng>
  auto operator()(Rng && rng) const -> CPP_ret(common_view<all_t<Rng>>)( //
  requires viewable_range<Rng> && (!common_range<Rng>))
  