Add an `ErrorGuaranteed` to `ast::TyKind::Err`.

This makes it more like `hir::TyKind::Err`, and avoids a
`span_delayed_bug` call in `LoweringContext::lower_ty_direct`.

It also requires adding `ast::TyKind::Dummy`, now that
`ast::TyKind::Err` can't be used for that purpose in the absence of an
error emission.

There are a couple of cases that aren't as neat as I would have liked,
marked with `FIXME` comments.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/tools/rustfmt/src/types.rs b/src/tools/rustfmt/src/types.rs
index 4cd8e6a703e..7f220a456a8 100644
--- a/src/tools/rustfmt/src/types.rs
+++ b/src/tools/rustfmt/src/types.rs
@@ -859,7 +859,7 @@ impl Rewrite for ast::Ty {
                 })
             }
             ast::TyKind::CVarArgs => Some("...".to_owned()),
-            ast::TyKind::Err => Some(context.snippet(self.span).to_owned()),
+            ast::TyKind::Dummy | ast::TyKind::Err(_) => Some(context.snippet(self.span).to_owned()),
             ast::TyKind::Typeof(ref anon_const) => rewrite_call(
                 context,
                 "typeof",