error: inherent impls cannot be default
  --> $DIR/validation.rs:7:1
   |
LL | default impl S {}
   | ^^^^^^^^^^^^^^^^^
   |
   = note: only trait implementations may be annotated with default

error: impls of auto traits cannot be default
  --> $DIR/validation.rs:9:1
   |
LL | default unsafe impl Send for S {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: impls of auto traits cannot be default
  --> $DIR/validation.rs:10:1
   |
LL | default impl !Send for Z {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0192]: negative impls are only allowed for auto traits (e.g., `Send` and `Sync`)
  --> $DIR/validation.rs:13:1
   |
LL | default impl !Tr for S {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0192`.