OCaml 5 system

[dhil]

We should add OCaml 5 as a system in place of Multicore OCaml.

[matijapretnar]

Perhaps in addition to Multicore OCaml (or some fork of OCaml 5) so as to benchmark multi-shot handlers?

[jO-Osko]

The plan is to add vanilla OCaml 5 and the multicont library that supports multi-shot handlers as a separate system

[dhil]

I should had written out the full plan. As Filip said the plan is to have two system instances of OCaml: OCaml 5 (vanilla) and OCaml 5 + multicont for multi-shot continuations.