Rollup merge of #147832 - aDotInTheVoid:rustdoc-format-options, r=GuillaumeGomez

rustdoc: Don't pass `RenderOptions` to `DocContext`

`RenderOptions` is full of HTML specific fields. The only ones that `DocContext` needs are `document_private` and `document_hidden`, which are accessable via `Cache` anyway.

Part of a larger campeign against `RenderOption`:
https://rust-lang.zulipchat.com/#narrow/channel/266220-t-rustdoc/topic/Using.20.60RenderOptions.60.20in.20less.20places.2E/with/545705812

Author: Zalathar