Upgrade to OCaml 5.0 as default

[sim642]

Closes #1003.

We can finally do this because mlgmpidl and apron have been released on opam for OCaml 5.0.

TODO

• Merge Upgrade to OCaml 5.0 gobview#26.

[sim642]

I did an sv-benchmarks run comparing OCaml 4.14 with OCaml 5.0 and the results are concerning. We might have to postpone making OCaml 5.0 the default and simply cherry-pick the changes from here to at least make Goblint OCaml 5.0 compatible, even if we don't use it by default.

Memory usage is significantly higher, almost 10× in some cases:

CPU time is also affected but that could be simply due to working with more memory:

(Full results)

[michael-schwarz]

Should we investigate what the performance is like with OCaml 5.1?

[sim642]

I tried 5.1 at some point and it wasn't much better, still a regression from 4.14.
OCaml 5.2 is around the corner, so that's another thing to try.

[michael-schwarz]

Sounds like 5.2 (released today) also won't fix our problems: https://discuss.ocaml.org/t/ocaml-5-2-0-released/14638

OCaml 5.2.0 is still a somewhat experimental release compared to the OCaml 4.14 branch. In particular

• [...]
• Ephemeron performances need to be investigated.

[FelixKrayer]

Just as a quick note here:
The version of the dependency of camlidl will have to be changed to version 1.12, as the current camlidl = 1.11 requires ocaml < 5.0.

[sim642]

All the dependencies in the Goblint lock file are for 4.14 anyway: the lock file also specifies OCaml 4.14. The non-locked dependencies allow appropriate versions to be installed on OCaml 5.0, 5.1 and 5.2.