Introduce `flattened_list` and use it to simplify `top_structure_tail_nodoc`. Inline `top_structure_tail_nodoc` at its single use site.
Introduce `flattened_list` and use it to simplify `top_structure_tail_nodoc`.
Inline `top_structure_tail_nodoc` at its single use site.

gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml