[rustdoc] Do not take doc(cfg()) into account when filtering doctests

[GuillaumeGomez]

Part of #147033.

Because it was using the extract_cfg_from_attrs common function, it was taking into account the doc(cfg()) attributes the same as if they were a cfg.

I didn't mark this PR as "fix" because I didn't handle the case of the doctest not being marked as ignored because I'm not sure if we should revisit the fact that we ignore these doctests or if we should just mark them as ignored (because of target_feature(enable = "...")).

Setting @fmease as reviewer as they are likely the only one with context about this issue. 😆

r? @fmease

[GuillaumeGomez]

And now it fails because we (doc) inlined some functions. Fixing that then. :)

[GuillaumeGomez]

Fixed CI \o/

[fmease]

I've only skimmed this function, so I'm wondering whether your added include_doc_cfg: bool parameter also accounts for inherited doc-cfgs. Like, do we still consider the doctest untestable and skip it in the code below?

#![feature(doc_cfg)]

#[doc(cfg(false))]
mod dummy {
    /// ```
    /// ```
    fn f() {}
}

View changes since the review

[GuillaumeGomez]

Damn, that's a good take. Ok, new approach: writing up a new function and stop using stuff we shouldn't. :)

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[GuillaumeGomez]

Reverted changes I made to extract_cfg_from_attrs and instead only look for the target_feature attributes.

[GuillaumeGomez]

Ah, new stuff gets added.

[rustbot]

stdarch is developed in its own repository. If possible, consider making this change to rust-lang/stdarch instead.

cc @Amanieu, @folkertdev, @sayantn