allow_internal

See the parent allow crate, or their shared GIT repo.

allow_internal is internal - to be used by allow crate only.

This could be simplified, or even eliminated (replaced + integrated into allow itself) if we used paste crate. But that would

• increase the built time, and
• complicate versioning.

Up to the future maintainers.

lib.rs:

NOT for public use. Only to be used by allow crate.