- // MIR for `main` before ConstProp
+ // MIR for `main` after ConstProp
  
  fn main() -> () {
      let mut _0: ();                      // return place in scope 0 at $DIR/mutable_variable.rs:4:11: 4:11
      let mut _1: i32;                     // in scope 0 at $DIR/mutable_variable.rs:5:9: 5:14
      scope 1 {
          debug x => _1;                   // in scope 1 at $DIR/mutable_variable.rs:5:9: 5:14
          let _2: i32;                     // in scope 1 at $DIR/mutable_variable.rs:7:9: 7:10
          scope 2 {
              debug y => _2;               // in scope 2 at $DIR/mutable_variable.rs:7:9: 7:10
          }
      }
  
      bb0: {
          StorageLive(_1);                 // scope 0 at $DIR/mutable_variable.rs:5:9: 5:14
          _1 = const 42_i32;               // scope 0 at $DIR/mutable_variable.rs:5:17: 5:19
                                           // ty::Const
                                           // + ty: i32
                                           // + val: Value(Scalar(0x0000002a))
                                           // mir::Constant
                                           // + span: $DIR/mutable_variable.rs:5:17: 5:19
                                           // + literal: Const { ty: i32, val: Value(Scalar(0x0000002a)) }
          _1 = const 99_i32;               // scope 1 at $DIR/mutable_variable.rs:6:5: 6:11
                                           // ty::Const
                                           // + ty: i32
                                           // + val: Value(Scalar(0x00000063))
                                           // mir::Constant
                                           // + span: $DIR/mutable_variable.rs:6:9: 6:11
                                           // + literal: Const { ty: i32, val: Value(Scalar(0x00000063)) }
          StorageLive(_2);                 // scope 1 at $DIR/mutable_variable.rs:7:9: 7:10
-         _2 = _1;                         // scope 1 at $DIR/mutable_variable.rs:7:13: 7:14
+         _2 = const 99_i32;               // scope 1 at $DIR/mutable_variable.rs:7:13: 7:14
+                                          // ty::Const
+                                          // + ty: i32
+                                          // + val: Value(Scalar(0x00000063))
+                                          // mir::Constant
+                                          // + span: $DIR/mutable_variable.rs:7:13: 7:14
+                                          // + literal: Const { ty: i32, val: Value(Scalar(0x00000063)) }
          _0 = const ();                   // scope 0 at $DIR/mutable_variable.rs:4:11: 8:2
                                           // ty::Const
                                           // + ty: ()
                                           // + val: Value(Scalar(<ZST>))
                                           // mir::Constant
                                           // + span: $DIR/mutable_variable.rs:4:11: 8:2
                                           // + literal: Const { ty: (), val: Value(Scalar(<ZST>)) }
          StorageDead(_2);                 // scope 1 at $DIR/mutable_variable.rs:8:1: 8:2
          StorageDead(_1);                 // scope 0 at $DIR/mutable_variable.rs:8:1: 8:2
          return;                          // scope 0 at $DIR/mutable_variable.rs:8:2: 8:2
      }
  }