- update to 3.12.0
* While fixing PR#4824, also corrected a gaping hole in the type checker,
which allowed instantiating separately object parameters and instance
variables in an interface. This hole was here since the beginning of
ocaml, and as a result many programs using object inheritance in a non
trivial way will need to be corrected. You can look at lablgtk2 for an
example.
* new language features, bugfixes