error[E0416]: identifier `x` is bound more than once in the same pattern
  --> $DIR/issue-3038.rs:12:15
   |
LL |       F::G(x, x) => { println!("{}", x + x); }
   |               ^ used in a pattern more than once

error[E0416]: identifier `x` is bound more than once in the same pattern
  --> $DIR/issue-3038.rs:17:32
   |
LL |       H::I(J::L(x, _), K::M(_, x))
   |                                ^ used in a pattern more than once

error[E0416]: identifier `x` is bound more than once in the same pattern
  --> $DIR/issue-3038.rs:23:13
   |
LL |         (x, x) => { x }
   |             ^ used in a pattern more than once

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0416`.