[PR] Drop Hack_caml.Sort module, no longer exists in 4.08
[PR] Drop Hack_caml.Sort module, no longer exists in 4.08

Summary:
Hi!

I was trying to use `flow_parser` on a project with OCaml 4.08 and realized that the `Hack_caml` module re-exports the now removed `Sort` module.

Figured I'd open a PR instead of keep the change in a fork indefinitely.

Thanks for the good work 🙌
Pull Request resolved: https://github.com/facebook/flow/pull/8057

Reviewed By: gabelevi

Differential Revision: D17158465

Pulled By: mroch

fbshipit-source-id: e465507f66969cf325bfd7315e8d49cb0ba08b32

nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow