Make visitors compatible with ppxlib 0.22.0
In ppxlib 0.22.0, the internal AST got bumped to ocaml 4.12. This commit adapts visitors to the compiler changes from 4.11 to 4.12: mainly, the introduction of injectivity to type declarations.
La vérification des quotas de chaque projet est mise en place en mode non bloquant. Plus d'information sur : https://doc-si.inria.fr/pages/viewpage.action?pageId=146834656
Quota verification is enabled for projects in non-blocking mode. More information: https://doc-si.inria.fr/pages/viewpage.action?pageId=146834656
In ppxlib 0.22.0, the internal AST got bumped to ocaml 4.12. This commit adapts visitors to the compiler changes from 4.11 to 4.12: mainly, the introduction of injectivity to type declarations.