Replace some instances of FxHashMap/FxHashSet with stable alternatives (mostly in rustc_hir and rustc_ast_lowering)

Part of https://github.com/rust-lang/compiler-team/issues/533

compiler/rustc_hir/src/def.rs

@@ -3,8 +3,8 @@ use crate::hir;
 
 use rustc_ast as ast;
 use rustc_ast::NodeId;
-use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::ToStableHashKey;
+use rustc_data_structures::unord::UnordMap;
 use rustc_macros::HashStable_Generic;
 use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::hygiene::MacroKind;
@@ -806,4 +806,4 @@ pub enum LifetimeRes {
     ElidedAnchor { start: NodeId, end: NodeId },
 }
 
-pub type DocLinkResMap = FxHashMap<(Symbol, Namespace), Option<Res<NodeId>>>;
+pub type DocLinkResMap = UnordMap<(Symbol, Namespace), Option<Res<NodeId>>>;

compiler/rustc_hir/src/definitions.rs

@@ -8,8 +8,8 @@ pub use crate::def_id::DefPathHash;
 use crate::def_id::{CrateNum, DefIndex, LocalDefId, StableCrateId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use crate::def_path_hash_map::DefPathHashMap;
 
-use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{Hash64, StableHasher};
+use rustc_data_structures::unord::UnordMap;
 use rustc_index::IndexVec;
 use rustc_span::symbol::{kw, sym, Symbol};
 
@@ -95,7 +95,7 @@ impl DefPathTable {
 #[derive(Debug)]
 pub struct Definitions {
     table: DefPathTable,
-    next_disambiguator: FxHashMap<(LocalDefId, DefPathData), u32>,
+    next_disambiguator: UnordMap<(LocalDefId, DefPathData), u32>,
 
     /// The [StableCrateId] of the local crate.
     stable_crate_id: StableCrateId,

compiler/rustc_hir/src/diagnostic_items.rs

@@ -1,12 +1,13 @@
 use crate::def_id::DefId;
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_span::def_id::DefIdMap;
 use rustc_span::Symbol;
 
 #[derive(Debug, Default)]
 pub struct DiagnosticItems {
-    pub id_to_name: FxHashMap<DefId, Symbol>,
-    pub name_to_id: FxHashMap<Symbol, DefId>,
+    pub id_to_name: DefIdMap<Symbol>,
+    pub name_to_id: FxIndexMap<Symbol, DefId>,
 }
 
 impl<CTX: crate::HashStableContext> HashStable<CTX> for DiagnosticItems {

compiler/rustc_hir/src/hir.rs

@@ -1,6 +1,6 @@
 use crate::def::{CtorKind, DefKind, Res};
-use crate::def_id::DefId;
-pub(crate) use crate::hir_id::{HirId, ItemLocalId, OwnerId};
+use crate::def_id::{DefId, LocalDefIdMap};
+pub(crate) use crate::hir_id::{HirId, ItemLocalId, ItemLocalMap, OwnerId};
 use crate::intravisit::FnKind;
 use crate::LangItem;
 
@@ -11,7 +11,6 @@ pub use rustc_ast::{BinOp, BinOpKind, BindingAnnotation, BorrowKind, ByRef, Capt
 pub use rustc_ast::{ImplPolarity, IsAuto, Movability, Mutability, UnOp};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sorted_map::SortedMap;
 use rustc_index::IndexVec;
 use rustc_macros::HashStable_Generic;
@@ -874,12 +873,12 @@ pub struct OwnerInfo<'hir> {
     /// Contents of the HIR.
     pub nodes: OwnerNodes<'hir>,
     /// Map from each nested owner to its parent's local id.
-    pub parenting: FxHashMap<LocalDefId, ItemLocalId>,
+    pub parenting: LocalDefIdMap<ItemLocalId>,
     /// Collected attributes of the HIR nodes.
     pub attrs: AttributeMap<'hir>,
     /// Map indicating what traits are in scope for places where this
     /// is relevant; generated by resolve.
-    pub trait_map: FxHashMap<ItemLocalId, Box<[TraitCandidate]>>,
+    pub trait_map: ItemLocalMap<Box<[TraitCandidate]>>,
 }
 
 impl<'tcx> OwnerInfo<'tcx> {

compiler/rustc_hir/src/pat_util.rs

@@ -1,7 +1,6 @@
 use crate::def::{CtorOf, DefKind, Res};
-use crate::def_id::DefId;
+use crate::def_id::{DefId, DefIdSet};
 use crate::hir::{self, BindingAnnotation, ByRef, HirId, PatKind};
-use rustc_data_structures::fx::FxHashSet;
 use rustc_span::symbol::Ident;
 use rustc_span::Span;
 
@@ -114,9 +113,9 @@ impl hir::Pat<'_> {
             }
             _ => true,
         });
-        // We remove duplicates by inserting into a `FxHashSet` to avoid re-ordering
+        // We remove duplicates by inserting into a hash set to avoid re-ordering
         // the bounds
-        let mut duplicates = FxHashSet::default();
+        let mut duplicates = DefIdSet::default();
         variants.retain(|def_id| duplicates.insert(*def_id));
         variants
     }