Use Place directly on check_mut_borrowing_layout_constrained_field, it's Copy

Author: spastorino

src/librustc_mir/transform/check_unsafety.rs

@@ -184,7 +184,7 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
         // because either of these would allow modifying the layout constrained field and
         // insert values that violate the layout constraints.
         if context.is_mutating_use() || context.is_borrow() {
-            self.check_mut_borrowing_layout_constrained_field(place, context.is_mutating_use());
+            self.check_mut_borrowing_layout_constrained_field(*place, context.is_mutating_use());
         }
 
         for (i, elem) in place.projection.iter().enumerate() {
@@ -382,7 +382,7 @@ impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
     }
     fn check_mut_borrowing_layout_constrained_field(
         &mut self,
-        place: &Place<'tcx>,
+        place: Place<'tcx>,
         is_mut_use: bool,
     ) {
         let mut cursor = place.projection.as_ref();