Kani module stubs for development

[ajrudzitis]

Requested feature: Kani module stubs for development
Use case:

Kani is currently difficult to use in an IDE because the kani module is only injected when running cargo kani. This means that while writing harnesses in the IDE along with my code, the IDE does not recognize any statements like kani::any(). This adds friction to writing new test harnesses and I cannot use facilities in the IDE to identify issues before I run my harness.

If there could a module published that provided stubs for the Kani API, it would be useful for allowing the IDE to do basic type checks, etc.

[celinval]

Yes, this is definitely something that's been in our radar. I think this would also play nicely with things like #2035.

I think the main question is how to ensure compatibility between the crate version a user is importing and the one Kani is using. Especially if dependencies start exporting things like Arbitrary implementation.