- Remove the renaming of Frama-C built-ins in the injector since the
  code printer is now responsible for it;
- Explicitely add calls to `store_block` (resp. `delete_block`) when
  allocating (resp. deallocating) a VLA.

Remove unused labelled argument and simplify the function as a result.

it seems like part of the issue lies in the fact that the cache might be looked
at from different cwd. Anyways, proposing an absolute location can't hurt.

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`.

code duplication started to become a bit problematic

All loop assigns corresponding to a given set of behaviors are now merged
together instead of being split into emitters. This is the same as what is done
for statement contracts and will make it much easier for callers to identify
appropriate loop assigns

Also uses kind names as labels.