When loading some state, it may happen that some annotations are found to have
been emitted by emitters that are no longer usable. This commit let the kernel
adopt them, keeping them available as was the case before refactoring
`Annotations.code_annot` to use `Annotations.code_annot_emitter`.

- Fix Value/Value#5
- Fix Value/Value#14

Some case studies (e.g. dyad) use some ugly casts from fd_set_t which lead
to the analysis stopping too early.
Changing the representation of fd_set_t should also help it better conform to
the standard (since a fd_set_t should be able to hold FD_SETSIZE elements).

[Ptests] preserve LOG after STDOPT directive

See merge request frama-c/frama-c!2073

This is absolutely not a sneaky attempt to relaunch a build (now that OCI seems
in better shape) pushing a nearly empty commit.