Make traits_in_crate and impls_in_crate proper queries and use them

[cjgillot]

We currently compute a list of all traits and all impls in a crate for metadata.
traits_in_crate is a query, and sorts all definitions by DefPathHash.
impls_in_crate is not a query, and sorts definitions by DefPathHash.

This PR suggests to:

• shift the sorting of traits_in_crate from the query to metadata encoding;
• use traits_in_crate for all analyses that iterate on traits;
• make impls_in_crate a query, keeping the sorting outside of the query in metadata encoding;
• use impls_in_crate for analyses that iterate on impls, like coherence.

The effect of the sorting on the definitions by DefPathHash is not obvious. The effect of sorting vs not sorting will need to investigated with respect to soundness of the crate_hash.

This issue may conflict with #94878, #95004 and #95082.

I am available on Zulip for further information.

[petrochenkov]

I'm not even sure traits_in_crate is necessary.

It's quite likely that we don't need the list of "all traits", but rather the list of "all traits with impls", in that case it can be extracted from impls_in_crate. This just needs some investigation and confirmation.

[Robert-Cunningham]

@rustbot claim

[Robert-Cunningham]

After investigating, I suspect that traits_in_crate it is necessary; even if we have a trait without an impl, it seems to me that we need to know about it to generate docs for it.

Let me know if there's something here I'm missing.

[mzacho]

@cjgillot is this still an issue? traits_in_crate and impls_in_crate both seem to have vanished from the code, and the queries

https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/query/mod.rs#L2147
https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/query/mod.rs#L2152

seem to do the job of collecting traits and impls in a crate.

Otherwise, if you'd update the description I can take a look at this.