Add variant/struct field search tab

[GuillaumeGomez]

Fixes #58229.

I'm just wondering if it's really useful though. Any other opinions would be very appreciated!

r? @QuietMisdreavus

[oli-obk]

At some point (when we get many of these), we should probably not make it a tab, but a dropdown menu

[GuillaumeGomez]

I'm open to any suggestions. :)

[QuietMisdreavus]

Is this searching for types being used in structs/variants, or for the names of the field/variant? If it's the latter, this tab is not useful - it's duplicating a subset of the first tab. I'm not familiar with how the search code looks at the index, and your screenshot makes it look like it's searching through names.

[Dylan-DPC-zz]

ping from triage @GuillaumeGomez @QuietMisdreavus what's the update on this?

[QuietMisdreavus]

I can't easily tell from reading the code whether this is searching for variants/fields by name or by type. If it's just a way to limit a name-based search to variants/fields (as the image in the PR description indicates), i don't think it's useful enough to include - they should already be included in the "In Names" tab.

---

It seems like the problem statement is something like this. Say you have the following crate:

pub struct SomeStruct;

pub struct OtherStruct {
  pub my_field: SomeStruct,
}

You should be able to search "SomeStruct" and get OtherStruct::my_field in the "In Variants/Fields" tab. That's a very useful feature that i would love to include.

[GuillaumeGomez]

I'll change this PR to go this way then. It'll match more what I had in mind to being with.

[bors]

☔ The latest upstream changes (presumably #59226) made this pull request unmergeable. Please resolve the merge conflicts.

[Centril]

Ping from triage, @GuillaumeGomez, what's the status of this PR?

[GuillaumeGomez]

Still requires to be done.

[GuillaumeGomez]

I'll reopen once I'm done.