Auto merge of #69649 - estebank:negative-impl-span, r=Centril

Tweak output for invalid negative impl errors

Follow up to #69722. Tweak negative impl errors emitted in the HIR:

```
error[E0192]: invalid negative impl
  --> $DIR/E0192.rs:9:6
   |
LL | impl !Trait for Foo { }
   |      ^^^^^^
   |
   = note: negative impls are only allowed for auto traits, like `Send` and `Sync`
```

src/librustdoc/visit_ast.rs

@@ -563,6 +563,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 polarity,
                 defaultness,
                 constness,
+                defaultness_span: _,
                 ref generics,
                 ref of_trait,
                 self_ty,