Use UnordMap and UnordSet for id collections (DefIdMap, LocalDefIdMap, etc)
This PR changes the `rustc_data_structures::define_id_collections!` macro to use `UnordMap` and `UnordSet` instead of `FxHashMap` and `FxHashSet`. This should account for a large portion of hash-maps being used in places where they can cause trouble.
The changes required are moderate but non-zero:
- In some places the collections are extracted into sorted vecs.
- There are a few instances where for-loops have been changed to extends.
~~Let's see what the performance impact is. With a bit more refactoring, we might be able to get rid of some of the additional sorting -- but the change set is already big enough. Unless there's a performance impact, I'd like to do further changes in subsequent PRs.~~
Performance does not seem to be negatively affected ([perf-run here](https://github.com/rust-lang/rust/pull/106977#issuecomment-1396776699)).
Part of [MCP 533](https://github.com/rust-lang/compiler-team/issues/533).
r? `@ghost`
This reverts commit 7d82cadd97acc66993b69304c5a1a04ef7d1fa36.
I am doing this to buy us some time with respect to issue #106337 w.r.t. the
1.67 release.
Fix bad import suggestion with nested `use` tree
Fixes#105566Fixes#105373
Ideally, we'd find some way to turn these into structured suggestions -- perhaps on a separate line as a different `use` statement, but I have no idea how to access the span for the whole `use` from this point in the import resolution code.
Point out span where we could introduce higher-ranked lifetime
Somewhat addresses #105422, but not really. We don't have that much useful information here since we're still in resolution :^(
Maybe this suggestion isn't worth it. If the reviewer has an idea how we can get a more succinct binder information for a structured suggestion, it would be appreciated.
add function to tell the identical errors for ambiguity_errors
if 2 errors of the kind and ident and span of the ident, b1, b2 and misc1 misc2 are the same we call these 2 ambiguity errors identical
prevent identical ambiguity error from pushing into vector of ambiguity_errors this will fix#105177
if 2 errors of the kind and ident and span of the ident, b1, b2 and misc1 misc2 are the same
then these 2 ambiguity errors matched
prevent identical ambiguity error from pushing into vector of ambiguity_errors
this will fix#105177
