perf(semantic): use oxc_allocator::HashMap in ScopeTree (#8554)

Use `oxc_allocator::HashMap` in `ScopeTree`, replacing `hashbrown::HashMap`. `oxc_allocator::HashMap` is non-drop, so it may reduce drop time of `ScopeTree` a little.

crates/oxc_semantic/Cargo.toml

@@ -30,7 +30,6 @@ oxc_span = { workspace = true }
 oxc_syntax = { workspace = true }
 
 assert-unchecked = { workspace = true }
-hashbrown = { workspace = true, features = ["allocator-api2"] }
 itertools = { workspace = true }
 phf = { workspace = true, features = ["macros"] }
 rustc-hash = { workspace = true }

crates/oxc_semantic/src/builder.rs

@@ -712,8 +712,7 @@ impl<'a> Visit<'a> for SemanticBuilder<'a> {
         if self.scope.get_flags(parent_scope_id).is_catch_clause() {
             self.scope.cell.with_dependent_mut(|allocator, inner| {
                 if !inner.bindings[parent_scope_id].is_empty() {
-                    let mut parent_bindings =
-                        Bindings::with_hasher_in(rustc_hash::FxBuildHasher, allocator);
+                    let mut parent_bindings = Bindings::new_in(allocator);
                     mem::swap(&mut inner.bindings[parent_scope_id], &mut parent_bindings);
                     for &symbol_id in parent_bindings.values() {
                         self.symbols.set_scope_id(symbol_id, self.current_scope_id);

crates/oxc_semantic/src/scope.rs

@@ -1,8 +1,6 @@
 use std::{fmt, mem};
 
-use rustc_hash::FxBuildHasher;
-
-use oxc_allocator::{Allocator, Vec as ArenaVec};
+use oxc_allocator::{Allocator, HashMap as ArenaHashMap, Vec as ArenaVec};
 use oxc_index::{Idx, IndexVec};
 use oxc_syntax::{
     node::NodeId,
@@ -13,9 +11,8 @@ use oxc_syntax::{
 
 use crate::SymbolTable;
 
-pub(crate) type Bindings<'a> = hashbrown::HashMap<&'a str, SymbolId, FxBuildHasher, &'a Allocator>;
-pub type UnresolvedReferences<'a> =
-    hashbrown::HashMap<&'a str, ArenaVec<'a, ReferenceId>, FxBuildHasher, &'a Allocator>;
+pub(crate) type Bindings<'a> = ArenaHashMap<'a, &'a str, SymbolId>;
+pub type UnresolvedReferences<'a> = ArenaHashMap<'a, &'a str, ArenaVec<'a, ReferenceId>>;
 
 /// Scope Tree
 ///
@@ -58,10 +55,7 @@ impl Default for ScopeTree {
             cell: ScopeTreeCell::new(Allocator::default(), |allocator| ScopeTreeInner {
                 bindings: IndexVec::new(),
                 child_ids: ArenaVec::new_in(allocator),
-                root_unresolved_references: UnresolvedReferences::with_hasher_in(
-                    FxBuildHasher,
-                    allocator,
-                ),
+                root_unresolved_references: UnresolvedReferences::new_in(allocator),
             }),
         }
     }
@@ -384,7 +378,7 @@ impl ScopeTree {
         let scope_id = self.parent_ids.push(parent_id);
         self.flags.push(flags);
         self.cell.with_dependent_mut(|allocator, inner| {
-            inner.bindings.push(Bindings::with_hasher_in(FxBuildHasher, allocator));
+            inner.bindings.push(Bindings::new_in(allocator));
         });
         self.node_ids.push(node_id);
         if self.build_child_ids {