- // MIR for `main` before ConstProp
+ // MIR for `main` after ConstProp
  
  fn main() -> () {
      let mut _0: ();                      // return place in scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:4:11: 4:11
      let mut _1: (i32, i32);              // in scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:5:9: 5:14
      scope 1 {
          debug x => _1;                   // in scope 1 at $DIR/mutable_variable_aggregate_mut_ref.rs:5:9: 5:14
          let _2: &mut (i32, i32);         // in scope 1 at $DIR/mutable_variable_aggregate_mut_ref.rs:6:9: 6:10
          scope 2 {
              debug z => _2;               // in scope 2 at $DIR/mutable_variable_aggregate_mut_ref.rs:6:9: 6:10
              let _3: (i32, i32);          // in scope 2 at $DIR/mutable_variable_aggregate_mut_ref.rs:8:9: 8:10
              scope 3 {
                  debug y => _3;           // in scope 3 at $DIR/mutable_variable_aggregate_mut_ref.rs:8:9: 8:10
              }
          }
      }
  
      bb0: {
          StorageLive(_1);                 // scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:5:9: 5:14
          (_1.0: i32) = const 42_i32;      // scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:5:17: 5:25
          (_1.1: i32) = const 43_i32;      // scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:5:17: 5:25
          StorageLive(_2);                 // scope 1 at $DIR/mutable_variable_aggregate_mut_ref.rs:6:9: 6:10
          _2 = &mut _1;                    // scope 1 at $DIR/mutable_variable_aggregate_mut_ref.rs:6:13: 6:19
          ((*_2).1: i32) = const 99_i32;   // scope 2 at $DIR/mutable_variable_aggregate_mut_ref.rs:7:5: 7:13
          StorageLive(_3);                 // scope 2 at $DIR/mutable_variable_aggregate_mut_ref.rs:8:9: 8:10
          _3 = _1;                         // scope 2 at $DIR/mutable_variable_aggregate_mut_ref.rs:8:13: 8:14
          nop;                             // scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:4:11: 9:2
          StorageDead(_3);                 // scope 2 at $DIR/mutable_variable_aggregate_mut_ref.rs:9:1: 9:2
          StorageDead(_2);                 // scope 1 at $DIR/mutable_variable_aggregate_mut_ref.rs:9:1: 9:2
          StorageDead(_1);                 // scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:9:1: 9:2
          return;                          // scope 0 at $DIR/mutable_variable_aggregate_mut_ref.rs:9:2: 9:2
      }
  }