Fix RLS toolstate after #54356 merge
Fixes toolstate regression caused by https://github.com/rust-lang/rust/pull/54356.
The `save::process_crate` now needs to be passed an additional `&Input`, this change contains the RLS equivalent of [this](https://github.com/rust-lang/rust/pull/54356/files#diff-707a0eda6b2f1a0537abc3d23133748cR983).
r? @kennytm (or @nrc if you're not away yet)