ProjectionElem::Subtype -> CastKind::Subtype

compiler/rustc_const_eval/src/check_consts/qualifs.rs

@@ -293,7 +293,6 @@ where
             ProjectionElem::Index(index) if in_local(index) => return true,
 
             ProjectionElem::Deref
-            | ProjectionElem::Subtype(_)
             | ProjectionElem::Field(_, _)
             | ProjectionElem::OpaqueCast(_)
             | ProjectionElem::ConstantIndex { .. }

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -133,7 +133,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 }
             }
 
-            CastKind::Transmute => {
+            CastKind::Transmute | CastKind::Subtype => {
                 assert!(src.layout.is_sized());
                 assert!(dest.layout.is_sized());
                 assert_eq!(cast_ty, dest.layout.ty); // we otherwise ignore `cast_ty` enirely...

compiler/rustc_const_eval/src/interpret/projection.rs

@@ -395,8 +395,6 @@ where
                 span_bug!(self.cur_span(), "OpaqueCast({ty}) encountered after borrowck")
             }
             UnwrapUnsafeBinder(target) => base.transmute(self.layout_of(target)?, self)?,
-            // We don't want anything happening here, this is here as a dummy.
-            Subtype(_) => base.transmute(base.layout(), self)?,
             Field(field, _) => self.project_field(base, field)?,
             Downcast(_, variant) => self.project_downcast(base, variant)?,
             Deref => self.deref_pointer(&base.to_op(self)?)?.into(),