`pid_type` and `proc_cm_event` are not tested.

[mbyx]

The previous ctest for inexplicable reasons hid the definitions of C enums when expanding macros and thus didn't test any C enum types. Now that the new ctest is able to test these types, it has been found that the pid_type and proc_cm_event C enums cannot be accessed on the C side, despite the correct headers being included.

It is suspected that the issue is because these types are not made public to user space C code, which is what is used for the tests.

I'm not exactly sure how this could be fixed.

This was first found in #4647.