- // MIR for `main` before ConstProp
+ // MIR for `main` after ConstProp
  
  fn main() -> () {
      let mut _0: ();
      let mut _1: (i32, i32);
      scope 1 {
          debug x => _1;
          let _2: &mut (i32, i32);
          scope 2 {
              debug z => _2;
              let _3: (i32, i32);
              scope 3 {
                  debug y => _3;
              }
          }
      }
  
      bb0: {
          StorageLive(_1);
          _1 = (const 42_i32, const 43_i32);
          StorageLive(_2);
          _2 = &mut _1;
          ((*_2).1: i32) = const 99_i32;
          StorageLive(_3);
          _3 = _1;
          _0 = const ();
          StorageDead(_3);
          StorageDead(_2);
          StorageDead(_1);
          return;
      }
  }