Auto merge of #120931 - chenyukang:yukang-cleanup-hashmap, r=michaelwoerister

Clean up potential_query_instability with FxIndexMap and UnordMap

From https://github.com/rust-lang/rust/pull/120485#issuecomment-1916437191

r? `@michaelwoerister`

compiler/rustc_hir_analysis/src/check/check.rs

@@ -1367,7 +1367,7 @@ fn check_type_alias_type_params_are_used<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalD
             // `Sized` bounds. If they came last for example, this would break `Trait + /*elab*/Sized`
             // since it would overwrite the span of the user-written bound. This could be fixed by
             // folding the spans with `Span::to` which requires a bit of effort I think.
-            .collect::<FxHashMap<_, _>>()
+            .collect::<FxIndexMap<_, _>>()
     });
 
     let mut params_used = BitSet::new_empty(generics.params.len());

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -1,7 +1,7 @@
 use super::potentially_plural_count;
 use crate::errors::{LifetimesOrBoundsMismatchOnTrait, MethodShouldReturnFuture};
 use hir::def_id::{DefId, DefIdMap, LocalDefId};
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
+use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_errors::{codes::*, pluralize, struct_span_code_err, Applicability, ErrorGuaranteed};
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -392,7 +392,7 @@ fn compare_method_predicate_entailment<'tcx>(
 
 struct RemapLateBound<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    mapping: &'a FxHashMap<ty::BoundRegionKind, ty::BoundRegionKind>,
+    mapping: &'a FxIndexMap<ty::BoundRegionKind, ty::BoundRegionKind>,
 }
 
 impl<'tcx> TypeFolder<TyCtxt<'tcx>> for RemapLateBound<'_, 'tcx> {
@@ -553,7 +553,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     // prove below that the hidden types are well formed.
     let universe = infcx.create_next_universe();
     let mut idx = 0;
-    let mapping: FxHashMap<_, _> = collector
+    let mapping: FxIndexMap<_, _> = collector
         .types
         .iter()
         .map(|(_, &(ty, _))| {
@@ -690,7 +690,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
                 // contains `def_id`'s early-bound regions.
                 let id_args = GenericArgs::identity_for_item(tcx, def_id);
                 debug!(?id_args, ?args);
-                let map: FxHashMap<_, _> = std::iter::zip(args, id_args)
+                let map: FxIndexMap<_, _> = std::iter::zip(args, id_args)
                     .skip(tcx.generics_of(trait_m.def_id).count())
                     .filter_map(|(a, b)| Some((a.as_region()?, b.as_region()?)))
                     .collect();
@@ -766,7 +766,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
 
 struct ImplTraitInTraitCollector<'a, 'tcx> {
     ocx: &'a ObligationCtxt<'a, 'tcx>,
-    types: FxHashMap<DefId, (Ty<'tcx>, ty::GenericArgsRef<'tcx>)>,
+    types: FxIndexMap<DefId, (Ty<'tcx>, ty::GenericArgsRef<'tcx>)>,
     span: Span,
     param_env: ty::ParamEnv<'tcx>,
     body_id: LocalDefId,
@@ -779,7 +779,7 @@ impl<'a, 'tcx> ImplTraitInTraitCollector<'a, 'tcx> {
         param_env: ty::ParamEnv<'tcx>,
         body_id: LocalDefId,
     ) -> Self {
-        ImplTraitInTraitCollector { ocx, types: FxHashMap::default(), span, param_env, body_id }
+        ImplTraitInTraitCollector { ocx, types: FxIndexMap::default(), span, param_env, body_id }
     }
 }
 
@@ -838,7 +838,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ImplTraitInTraitCollector<'_, 'tcx> {
 
 struct RemapHiddenTyRegions<'tcx> {
     tcx: TyCtxt<'tcx>,
-    map: FxHashMap<ty::Region<'tcx>, ty::Region<'tcx>>,
+    map: FxIndexMap<ty::Region<'tcx>, ty::Region<'tcx>>,
     num_trait_args: usize,
     num_impl_args: usize,
     def_id: DefId,

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -76,7 +76,7 @@ pub use check::check_abi;
 
 use std::num::NonZeroU32;
 
-use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::ErrorGuaranteed;
 use rustc_errors::{pluralize, struct_span_code_err, Diagnostic, DiagnosticBuilder};
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -307,7 +307,7 @@ fn bounds_from_generic_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: impl IntoIterator<Item = (ty::Clause<'tcx>, Span)>,
 ) -> (String, String) {
-    let mut types: FxHashMap<Ty<'tcx>, Vec<DefId>> = FxHashMap::default();
+    let mut types: FxIndexMap<Ty<'tcx>, Vec<DefId>> = FxIndexMap::default();
     let mut projections = vec![];
     for (predicate, _) in predicates {
         debug!("predicate {:?}", predicate);