Auto merge of #9772 - lukas-code:doc-spans, r=Manishearth

Shrink `missing_{safety,errors,panics}_doc` spans

Shrink the spans of `clippy::missing_*_doc` to match `missing_docs` and don't cover the entire item anymore. This helps readability in IDEs by not coloring the entire screen yellow, similar to https://github.com/rust-lang/rust/pull/103749 and https://github.com/rust-lang/rust/pull/90761.

before:
![image](https://user-images.githubusercontent.com/26522220/199483288-af0cf0c2-a9e4-47a8-81e3-50ccf380d939.png)

after:
![image](https://user-images.githubusercontent.com/26522220/199483366-445e5ddd-9f71-4de1-85be-43461c9b7d5d.png)

changelog: [`missing_safety_doc`], [`missing_error_doc`], [`missing_panics_doc`]: These lints no longer span the entire item.