Per the [Standard Library development guide](https://std-dev-guide.rust-lang.org/code-considerations/performance/inline.html):
> You can add `#[inline]`:
>
> - To public, small, non-generic functions.
>
> You shouldn't need `#[inline]`:
> - On methods that have any generics in scope.
> - On methods on traits that don't have a default implementation.
>
> `#[inline]` can always be introduced later, so if you're in doubt they can just be removed.
This PR follows this guideline to reduce the number of `#[inline]` annotations in our code, removing the annotation in:
- Non-public functions
- Generic functions
- Medium and big functions.
Hopefully this shouldn't impact our perf at all, but let's wait to see the benchmark results.
José Julián Espina
cc45a827ca