Update bindings

In order to update the pre-generated bindings:

Update pre-generated bindings

UPDATE_CAPSTONE_BINDINGS=1 cargo build --features use_bindgen

If needed, format the result (might be necessary; sometimes the source has been one big line).
```
rustfmt pre_generated/*.rs
```
Commit bindings update.
```
git commit "pre_generated/*.rs"
```

Notes

We used to separately fix-up the documentation after updating the pre-generated bindings, but now bindgen correctly parses comments.