Auto merge of #147867 - cjgillot:invalidate-cleanup, r=tmiasko

Stop invalidating CFG caches in CleanupPostBorrowck.
r? `@ghost`

Author: bors

compiler/rustc_mir_transform/src/cleanup_post_borrowck.rs

@@ -17,15 +17,17 @@
 //! [`SpanMarker`]: rustc_middle::mir::coverage::CoverageKind::SpanMarker
 
 use rustc_middle::mir::coverage::CoverageKind;
-use rustc_middle::mir::{Body,BorrowKind,CastKind,Rvalue,StatementKind,TerminatorKind};
+use rustc_middle::mir::*;
 use rustc_middle::ty::TyCtxt;
 use rustc_middle::ty::adjustment::PointerCoercion;
 
 pub(super)structCleanupPostBorrowck;
 
 impl<'tcx>crate::MirPass<'tcx>forCleanupPostBorrowck{
 fnrun_pass(&self,_tcx:TyCtxt<'tcx>,body:&mutBody<'tcx>){
-for basic_block in body.basic_blocks.as_mut(){
+// Manually invalidate CFG caches if we actually change a terminator's edges.
+letmut invalidate_cfg = false;
+for basic_block in body.basic_blocks.as_mut_preserves_cfg().iter_mut(){
 for statement in basic_block.statements.iter_mut(){
 match statement.kind{
 StatementKind::AscribeUserType(..)
@@ -59,16 +61,23 @@ impl<'tcx> crate::MirPass<'tcx> for CleanupPostBorrowck {
  _ => (),
 }
 }
+
+// If we change any terminator, we need to ensure that we invalidated the CFG cache.
 let terminator = basic_block.terminator_mut();
 match terminator.kind{
 TerminatorKind::FalseEdge{ real_target, .. }
  | TerminatorKind::FalseUnwind{ real_target, .. } => {
+ invalidate_cfg = true;
  terminator.kind = TerminatorKind::Goto{target: real_target };
 }
  _ => {}
 }
 }
 
+if invalidate_cfg {
+ body.basic_blocks.invalidate_cfg_cache();
+}
+
  body.user_type_annotations.raw.clear();
 
 for decl in&mut body.local_decls{