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.

2 files changed, 2 insertions, 2 deletions

diff --git a/src/tools/clippy/clippy_utils/src/ast_utils.rs b/src/tools/clippy/clippy_utils/src/ast_utils.rs
index adc35bd82ae..0467a8a6570 100644
--- a/src/tools/clippy/clippy_utils/src/ast_utils.rs
+++ b/src/tools/clippy/clippy_utils/src/ast_utils.rs
@@ -690,7 +690,7 @@ pub fn eq_ty(l: &Ty, r: &Ty) -> bool {
     match (&l.kind, &r.kind) {
         (Paren(l), _) => eq_ty(l, r),
         (_, Paren(r)) => eq_ty(l, r),
-        (Never, Never) | (Infer, Infer) | (ImplicitSelf, ImplicitSelf) | (Err, Err) | (CVarArgs, CVarArgs) => true,
+        (Never, Never) | (Infer, Infer) | (ImplicitSelf, ImplicitSelf) | (Err(_), Err(_)) | (CVarArgs, CVarArgs) => true,
         (Slice(l), Slice(r)) => eq_ty(l, r),
         (Array(le, ls), Array(re, rs)) => eq_ty(le, re) && eq_expr(&ls.value, &rs.value),
         (Ptr(l), Ptr(r)) => l.mutbl == r.mutbl && eq_ty(&l.ty, &r.ty),
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",