- // MIR for `dereference_reborrow` before GVN
+ // MIR for `dereference_reborrow` after GVN
  
  fn dereference_reborrow(_1: &mut u8) -> () {
      debug mut_a => _1;
      let mut _0: ();
      let _2: &u8;
      scope 1 {
          debug a => _2;
          let _3: u8;
          scope 2 {
              debug b => _3;
              let _4: u8;
              scope 3 {
                  debug c => _4;
              }
          }
      }
  
      bb0: {
          StorageLive(_2);
          _2 = &(*_1);
          StorageLive(_3);
          _3 = copy (*_2);
          StorageLive(_4);
-         _4 = copy (*_2);
+         _4 = copy _3;
          _0 = const ();
          StorageDead(_4);
          StorageDead(_3);
          StorageDead(_2);
          return;
      }
  }
  
