monads: `core_kernel.rope` no longer exists in v0.16

[bmourad01]

It seems this functionality has been separated into the jane_rope package (which currently depends on base v0.16). Would we need to break compatibility with previous versions (i.e. < v0.16.0) of janestreet libraries to upgrade, or hard stop at v0.15? Perhaps a third option exists?

ping @ivg

[ivg]

Do you mean by a hard stop that we shouldn't support versions below v0.15 or above?

[bmourad01]

By that I mean that one option would be to not support anything above v0.15.

[XVilka]

It's better to support newer Core/Base versions in my opinion, since they will benefit from all the OCaml 5.x multicore and effects work in the future, which would fit BAP quite well for variety of reasons. See also #1561