rust: declare generated functions as inline able

[crop2000]

I think it should make sense to add a #[inline] declaration to most functions generated by faust. here a example how the generated code would look like: example

The main benefit of explicit inline declaration is that functions can be in-lined across crate boundaries.

there are some things to consider in relation to this as discussed here: https://matklad.github.io/2021/07/09/inline-in-rust.html the small examples and faust2* projects should not be affected by this change as far as I understood.

do you have opinions on this? @bluenote10