Rollup merge of #134491 - compiler-errors:dtor-tweaks, r=lqd

Some destructor/drop related tweaks

Two random tweaks I got from investigating some stuff around drops in edition 2024:
1. Use the `TypingEnv` of the mir builder, rather than making it over again.
2. Rename the `id` field from `Scope` to `local_id`, to reflect that it's a local id, and remove the `item_local_id()` accessor which just returned the id field.

compiler/rustc_middle/src/middle/region.rs

@@ -84,23 +84,23 @@ use crate::ty::TyCtxt;
 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash, Copy, TyEncodable, TyDecodable)]
 #[derive(HashStable)]
 pub struct Scope {
-    pub id: hir::ItemLocalId,
+    pub local_id: hir::ItemLocalId,
     pub data: ScopeData,
 }
 
 impl fmt::Debug for Scope {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.data {
-            ScopeData::Node => write!(fmt, "Node({:?})", self.id),
-            ScopeData::CallSite => write!(fmt, "CallSite({:?})", self.id),
-            ScopeData::Arguments => write!(fmt, "Arguments({:?})", self.id),
-            ScopeData::Destruction => write!(fmt, "Destruction({:?})", self.id),
-            ScopeData::IfThen => write!(fmt, "IfThen({:?})", self.id),
-            ScopeData::IfThenRescope => write!(fmt, "IfThen[edition2024]({:?})", self.id),
+            ScopeData::Node => write!(fmt, "Node({:?})", self.local_id),
+            ScopeData::CallSite => write!(fmt, "CallSite({:?})", self.local_id),
+            ScopeData::Arguments => write!(fmt, "Arguments({:?})", self.local_id),
+            ScopeData::Destruction => write!(fmt, "Destruction({:?})", self.local_id),
+            ScopeData::IfThen => write!(fmt, "IfThen({:?})", self.local_id),
+            ScopeData::IfThenRescope => write!(fmt, "IfThen[edition2024]({:?})", self.local_id),
             ScopeData::Remainder(fsi) => write!(
                 fmt,
                 "Remainder {{ block: {:?}, first_statement_index: {}}}",
-                self.id,
+                self.local_id,
                 fsi.as_u32(),
             ),
         }
@@ -164,18 +164,8 @@ rustc_index::newtype_index! {
 rustc_data_structures::static_assert_size!(ScopeData, 4);
 
 impl Scope {
-    /// Returns an item-local ID associated with this scope.
-    ///
-    /// N.B., likely to be replaced as API is refined; e.g., pnkfelix
-    /// anticipates `fn entry_node_id` and `fn each_exit_node_id`.
-    pub fn item_local_id(&self) -> hir::ItemLocalId {
-        self.id
-    }
-
     pub fn hir_id(&self, scope_tree: &ScopeTree) -> Option<HirId> {
-        scope_tree
-            .root_body
-            .map(|hir_id| HirId { owner: hir_id.owner, local_id: self.item_local_id() })
+        scope_tree.root_body.map(|hir_id| HirId { owner: hir_id.owner, local_id: self.local_id })
     }
 
     /// Returns the span of this `Scope`. Note that in general the
@@ -350,7 +340,7 @@ impl ScopeTree {
 
     pub fn record_var_scope(&mut self, var: hir::ItemLocalId, lifetime: Scope) {
         debug!("record_var_scope(sub={:?}, sup={:?})", var, lifetime);
-        assert!(var != lifetime.item_local_id());
+        assert!(var != lifetime.local_id);
         self.var_map.insert(var, lifetime);
     }
 
@@ -359,7 +349,7 @@ impl ScopeTree {
         match &candidate_type {
             RvalueCandidateType::Borrow { lifetime: Some(lifetime), .. }
             | RvalueCandidateType::Pattern { lifetime: Some(lifetime), .. } => {
-                assert!(var.local_id != lifetime.item_local_id())
+                assert!(var.local_id != lifetime.local_id)
             }
             _ => {}
         }

compiler/rustc_middle/src/ty/rvalue_scopes.rs

@@ -35,7 +35,7 @@ impl RvalueScopes {
         // if there's one. Static items, for instance, won't
         // have an enclosing scope, hence no scope will be
         // returned.
-        let mut id = Scope { id: expr_id, data: ScopeData::Node };
+        let mut id = Scope { local_id: expr_id, data: ScopeData::Node };
         let mut backwards_incompatible = None;
 
         while let Some(&(p, _)) = region_scope_tree.parent_map.get(&id) {
@@ -60,7 +60,7 @@ impl RvalueScopes {
                     if backwards_incompatible.is_none() {
                         backwards_incompatible = region_scope_tree
                             .backwards_incompatible_scope
-                            .get(&p.item_local_id())
+                            .get(&p.local_id)
                             .copied();
                     }
                     id = p
@@ -76,7 +76,7 @@ impl RvalueScopes {
     pub fn record_rvalue_scope(&mut self, var: hir::ItemLocalId, lifetime: Option<Scope>) {
         debug!("record_rvalue_scope(var={var:?}, lifetime={lifetime:?})");
         if let Some(lifetime) = lifetime {
-            assert!(var != lifetime.item_local_id());
+            assert!(var != lifetime.local_id);
         }
         self.map.insert(var, lifetime);
     }