rust-filepatterns: don't `Box` subincludes unnecessarily This was caught by `clippy`.

rust-nodemap: implement `PartialEq` without allocation This was caught by `clippy`. It's probable that this ends up optimized out by the compiler, but let's not rely on that.

rust-clippy: tell `clippy` we don't need to declare a default here This is a struct only useful for tests.

rust-clippy: refactor complex type This makes reading the signature a bit less tiring.

rust-clippy: simplify return type of debug function This makes the type a little bit more readable.

rust-clippy: add `is_empty` method to please the `clippy` gods I can see it being useful anyway.