Auto merge of #106977 - michaelwoerister:unord_id_collections, r=oli-obk

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`

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -391,7 +391,7 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
             // keys from the former.
             // This is a rudimentary check that does not catch all cases,
             // just the easiest.
-            let mut fallback_map: DefIdMap<DefId> = Default::default();
+            let mut fallback_map: Vec<(DefId, DefId)> = Default::default();
 
             // Issue 46112: We want the map to prefer the shortest
             // paths when reporting the path to an item. Therefore we
@@ -421,12 +421,12 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
 
                 if let Some(def_id) = child.res.opt_def_id() {
                     if child.ident.name == kw::Underscore {
-                        fallback_map.insert(def_id, parent);
+                        fallback_map.push((def_id, parent));
                         return;
                     }
 
                     if ty::util::is_doc_hidden(tcx, parent) {
-                        fallback_map.insert(def_id, parent);
+                        fallback_map.push((def_id, parent));
                         return;
                     }
 
@@ -460,6 +460,7 @@ pub(in crate::rmeta) fn provide(providers: &mut Providers) {
             // Fill in any missing entries with the less preferable path.
             // If this path re-exports the child as `_`, we still use this
             // path in a diagnostic that suggests importing `::*`.
+
             for (child, parent) in fallback_map {
                 visible_parent_map.entry(child).or_insert(parent);
             }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1187,8 +1187,11 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 record!(self.tables.trait_impl_trait_tys[def_id] <- table);
             }
         }
-        let inherent_impls = tcx.crate_inherent_impls(());
-        for (def_id, implementations) in inherent_impls.inherent_impls.iter() {
+        let inherent_impls = tcx.with_stable_hashing_context(|hcx| {
+            tcx.crate_inherent_impls(()).inherent_impls.to_sorted(&hcx, true)
+        });
+
+        for (def_id, implementations) in inherent_impls {
             if implementations.is_empty() {
                 continue;
             }