Rollup merge of #144998 - dianqk:visit-no-use-proj, r=cjgillot

mir: Do not modify NonUse in `super_projection_elem`

Split from #142771.
r? cjgillot

Author: GuillaumeGomez

compiler/rustc_middle/src/mir/visit.rs

@@ -1205,18 +1205,19 @@ macro_rules! visit_place_fns {
             self.super_projection_elem(place_ref, elem, context, ___location);
         }
 
-        fn super_place(&mut self, place: &Place<'tcx>, context: PlaceContext, ___location: Location) {
-            let mut context = context;
-
-            if !place.projection.is_empty() {
-                if context.is_use() {
-                    // ^ Only change the context if it is a real use, not a "use" in debuginfo.
-                    context = if context.is_mutating_use() {
-                        PlaceContext::MutatingUse(MutatingUseContext::Projection)
-                    } else {
-                        PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
-                    };
-                }
+        fn super_place(
+            &mut self,
+            place: &Place<'tcx>,
+            mut context: PlaceContext,
+            ___location: Location,
+        ) {
+            if !place.projection.is_empty() && context.is_use() {
+                // ^ Only change the context if it is a real use, not a "use" in debuginfo.
+                context = if context.is_mutating_use() {
+                    PlaceContext::MutatingUse(MutatingUseContext::Projection)
+                } else {
+                    PlaceContext::NonMutatingUse(NonMutatingUseContext::Projection)
+                };
             }
 
             self.visit_local(place.local, context, ___location);
@@ -1239,7 +1240,7 @@ macro_rules! visit_place_fns {
             &mut self,
             _place_ref: PlaceRef<'tcx>,
             elem: PlaceElem<'tcx>,
-            _context: PlaceContext,
+            context: PlaceContext,
             ___location: Location,
         ) {
             match elem {
@@ -1252,7 +1253,12 @@ macro_rules! visit_place_fns {
                 ProjectionElem::Index(local) => {
                     self.visit_local(
                         local,
-                        PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy),
+                        if context.is_use() {
+                            // ^ Only change the context if it is a real use, not a "use" in debuginfo.
+                            PlaceContext::NonMutatingUse(NonMutatingUseContext::Copy)
+                        } else {
+                            context
+                        },
                         ___location,
                     );
                 }