Auto merge of #53002 - QuietMisdreavus:brother-may-i-have-some-loops, r=pnkfelix

Auto merge of #53002 - QuietMisdreavus:brother-may-i-have-some-loops, r=pnkfelix

make `everybody_loops` preserve item declarations

First half of https://github.com/rust-lang/rust/issues/52545.

`everybody_loops` is used by rustdoc to ensure we don't contain erroneous references to platform APIs if one of its uses is pulled in by `#[doc(cfg)]`. However, you can also implement traits for public types inside of functions. This is used by Diesel (probably others, but they were the example that was reported) to get around a recent macro hygiene fix, which has caused their crate to fail to document. While this won't make the traits show up in documentation (that step comes later), it will at least allow files to be generated.