PinDerefMutHelper should not show up in impl DerefMut for Pin #147998
Description
Location (URL)
https://doc.rust-lang.org/nightly/std/pin/struct.Pin.html#impl-DerefMut-for-Pin%3CPtr%3E
Summary
The PR #145608 explicitly contains measures using #[cfg(doc)] to ensure that the docs are rendered in a certain way. This works locally, as can be seen from the locally generated docs in #145608 (comment), but on doc.rust-lang.org this does not seem to apply.
Perhaps --cfg doc is not applied when building docs for the website, even though they are applied locally?