Auto merge of #116170 - matthewjasper:remove-thir-destruction-scopes, r=cjgillot

Don't include destruction scopes in THIR

They are not used by anyone, and add memory/performance overhead.

compiler/rustc_middle/src/middle/region.rs

@@ -349,10 +349,6 @@ impl ScopeTree {
         }
     }
 
-    pub fn opt_destruction_scope(&self, n: hir::ItemLocalId) -> Option<Scope> {
-        self.destruction_scopes.get(&n).cloned()
-    }
-
     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());

compiler/rustc_middle/src/thir.rs

@@ -134,7 +134,6 @@ pub struct Block {
     /// This does *not* include labels on loops, e.g. `'label: loop {}`.
     pub targeted_by_break: bool,
     pub region_scope: region::Scope,
-    pub opt_destruction_scope: Option<region::Scope>,
     /// The span of the block, including the opening braces,
     /// the label, and the `unsafe` keyword, if present.
     pub span: Span,
@@ -193,7 +192,6 @@ pub enum BlockSafety {
 #[derive(Clone, Debug, HashStable)]
 pub struct Stmt<'tcx> {
     pub kind: StmtKind<'tcx>,
-    pub opt_destruction_scope: Option<region::Scope>,
 }
 
 #[derive(Clone, Debug, HashStable)]
@@ -1224,12 +1222,12 @@ impl<'tcx> fmt::Display for Pat<'tcx> {
 mod size_asserts {
     use super::*;
     // tidy-alphabetical-start
-    static_assert_size!(Block, 56);
+    static_assert_size!(Block, 48);
     static_assert_size!(Expr<'_>, 64);
     static_assert_size!(ExprKind<'_>, 40);
     static_assert_size!(Pat<'_>, 64);
     static_assert_size!(PatKind<'_>, 48);
-    static_assert_size!(Stmt<'_>, 56);
+    static_assert_size!(Stmt<'_>, 48);
     static_assert_size!(StmtKind<'_>, 48);
     // tidy-alphabetical-end
 }