Add support for OCaml 5.1

[kit-ty-kate]

ocamlbuildlib and the ocamlbuild binary were wrongly compiled.

See https://github.com/dbuenzli/mtime/issues/45

[gasche]

Thanks!

The problem that you are fixing is that the Makefile is incorrect, it compiles all source files with -for-pack but only some of them are packed. (I guess that before this mistake was ignored by the compiler, and now it isn't anymore.)

Your fix is to create new source directories: only the files to be packed remain in src/, other library files go in plugin-lib/ and binaries go in bin/.

There are however two issues with the proposed change as-is, which should be relatively easy to fix:

• ocamlbuild is able to bootstrap itself (make -C bootstrap), this is useful for testing purposes, and I believe the change breaks this bootstrap; one would need to update the boostrap build to the new source locations
• as can be observed in the bootstrap build files in bootstrap/, which provide a rather clear specification of the intent of the ocamlbuild build, the first iteration of this PR puts some files in the wrong directory:
  • ppcache and ocamlbuildlight should go in bin/
  • the files remaining in src/ should be only thosee listed in bootstrap/ocamlbuild_pack.mlpack or Makefile/$PACK_CMO

[kit-ty-kate]

Done

[gasche]

Very nice, thanks!

[gasche]

(Do you have the necessary privileges to do a release, and would you be willing to do it? I hate releasing.)

[kit-ty-kate]

Done https://github.com/ocaml/opam-repository/pull/22182

[gasche]

You're the best.