Sandmark breaks on OCaml 4.14.0+trunk

[kayceesrk]

See the failure in the CI at https://cloud.drone.io/ocaml-bench/sandmark/840/1/2. It would be useful to keep the CI green in the next few months as we head towards upstreaming multicore.

[kayceesrk]

@shubhamkumar13 This is high-priority for the compiler team. Please let's work on this.

[shubhamkumar13]

Yes I did looked into it yesterday and the issue seemed to be the dune variant.
The error log did mention it

<><> Error report <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
+- The following actions failed
| - build dune 2.8.1
+- 

But updating the dune version didn't fix it, there seem to be a lot of packages that might need updating and didn't build with trunk (I'm not sure why) which I'm planning to look at. I have the error log here.

[kayceesrk]

Thanks. Many packages are not expected to work with trunk. This may be due to several reasons. (1) It may be that trunk introduces a breaking change that makes the package not build with trunk. (2) It may be that the upper limit of the constraint is less than trunk's version; trunk always bumps the version number after a release.

[shubhamkumar13]

I tried to update the dependency packages to make sandmark work with 4.14.0+trunk.
There are still some of the packages which are still not working with 4.14.0+trunk.

react
rresult
fmt
astring
mtime
ocaml-migrate-parsetree

The packages react, rresult, fmt, astring have the same error related to Toploop.use_file .
There seem to be changes in the toploop interface (found a similar issue related to tooploop in ocaml/ocaml#10461 (comment))

I also tested my branch with the other ci workflows locally and it seems to work without any issues.

[shubhamkumar13]

#251 resolves this issue