Auto merge of #97383 - dingxiangfei2009:restore-region-scope-tree-query, r=dingxiangfei2009

Try to cache region_scope_tree as a query

This PR will attempt to restore `region_scope_tree` as a query so that caching works again. It seems that `region_scope_tree` could be re-computed for nested items after all, which could explain the performance regression introduced by #95563.

cc `@Mark-Simulacrum` `@pnkfelix` I will try to trigger a perf run here.

1 files changed, 0 insertions, 8 deletions

diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 6b92a4c0a2e..3c08db5dc68 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -6,7 +6,6 @@ use crate::hir::place::Place as HirPlace;
 use crate::infer::canonical::{Canonical, CanonicalVarInfo, CanonicalVarInfos};
 use crate::lint::{struct_lint_level, LintDiagnosticBuilder, LintLevelSource};
 use crate::middle::codegen_fn_attrs::CodegenFnAttrs;
-use crate::middle::region::ScopeTree;
 use crate::middle::resolve_lifetime::{self, LifetimeScopeForPath};
 use crate::middle::stability;
 use crate::mir::interpret::{self, Allocation, ConstAllocation, ConstValue, Scalar};
@@ -538,12 +537,6 @@ pub struct TypeckResults<'tcx> {
     /// issue by fake reading `t`.
     pub closure_fake_reads: FxHashMap<DefId, Vec<(HirPlace<'tcx>, FakeReadCause, hir::HirId)>>,
 
-    /// Tracks critical information about regions in a body.
-    /// This includes containment relationship between regions,
-    /// liveness relationship between variables and regions and
-    /// information about yield points.
-    pub region_scope_tree: ScopeTree,
-
     /// Tracks the rvalue scoping rules which defines finer scoping for rvalue expressions
     /// by applying extended parameter rules.
     /// Details may be find in `rustc_typeck::check::rvalue_scopes`.
@@ -586,7 +579,6 @@ impl<'tcx> TypeckResults<'tcx> {
             concrete_opaque_types: Default::default(),
             closure_min_captures: Default::default(),
             closure_fake_reads: Default::default(),
-            region_scope_tree: Default::default(),
             rvalue_scopes: Default::default(),
             generator_interior_types: ty::Binder::dummy(Default::default()),
             treat_byte_string_as_slice: Default::default(),