error[E0599]: no method named `x` found for struct `S` in the current scope
  --> $DIR/arbitrary_self_types_needing_mut_pin.rs:11:7
   |
LL | struct S;
   | -------- method `x` not found for this struct
...
LL |     fn x(self: Pin<&mut Self>) {
   |        - the method is available for `Pin<&mut S>` here
...
LL |     S.x();
   |       ^ method not found in `S`
   |
help: consider wrapping the receiver expression with the appropriate type
   |
LL |     Pin::new(&mut S).x();
   |     +++++++++++++  +

error: aborting due to previous error

For more information about this error, try `rustc --explain E0599`.