more type sanity checks in Miri

Author: RalfJung

src/librustc_mir/interpret/operand.rs

@@ -469,6 +469,13 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             .try_fold(base_op, |op, elem| self.operand_projection(op, elem))?;
 
         trace!("eval_place_to_op: got {:?}", *op);
+        // Sanity-check the type we ended up with.
+        debug_assert_eq!(
+            self.subst_from_current_frame_and_normalize_erasing_regions(
+                place.ty(&self.frame().body.local_decls, *self.tcx).ty
+            ),
+            op.layout.ty,
+        );
         Ok(op)
     }
 

src/librustc_mir/interpret/place.rs

@@ -638,6 +638,13 @@ where
         }
 
         self.dump_place(place_ty.place);
+        // Sanity-check the type we ended up with.
+        debug_assert_eq!(
+            self.subst_from_current_frame_and_normalize_erasing_regions(
+                place.ty(&self.frame().body.local_decls, *self.tcx).ty
+            ),
+            place_ty.layout.ty,
+        );
         Ok(place_ty)
     }