error[E06001]: unused value without 'drop'
  ┌─ tests/move_check/locals/reassign_parameter.move:7:9
  │  
2 │       struct R {}
  │              - To satisfy the constraint, the 'drop' ability would need to be added here
3 │   
4 │       public fun reassign_parameter(r: R) {
  │                                        - The type '0x8675309::M::R' does not have the ability 'drop'
5 │           let R { } = r;
6 │           r = R {};
  │           - The parameter 'r' might still contain a value. The value does not have the 'drop' ability and must be consumed before the function returns
7 │ ╭         if  (true) {
8 │ │             let R { } = r;
9 │ │         }
  │ ╰─────────^ Invalid return