- // MIR for `arg_src` before CopyProp
+ // MIR for `arg_src` after CopyProp
  
  fn arg_src(_1: i32) -> i32 {
      debug x => _1;                       // in scope 0 at $DIR/copy_propagation_arg.rs:+0:12: +0:17
      let mut _0: i32;                     // return place in scope 0 at $DIR/copy_propagation_arg.rs:+0:27: +0:30
      let _2: i32;                         // in scope 0 at $DIR/copy_propagation_arg.rs:+1:9: +1:10
      scope 1 {
          debug y => _2;                   // in scope 1 at $DIR/copy_propagation_arg.rs:+1:9: +1:10
      }
  
      bb0: {
          StorageLive(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+1:9: +1:10
          _2 = _1;                         // scope 0 at $DIR/copy_propagation_arg.rs:+1:13: +1:14
          _1 = const 123_i32;              // scope 1 at $DIR/copy_propagation_arg.rs:+2:5: +2:12
          _0 = _2;                         // scope 1 at $DIR/copy_propagation_arg.rs:+3:5: +3:6
          StorageDead(_2);                 // scope 0 at $DIR/copy_propagation_arg.rs:+4:1: +4:2
          return;                          // scope 0 at $DIR/copy_propagation_arg.rs:+4:2: +4:2
      }
  }