Auto merge of rust-lang#120586 - ShE3py:exprkind-err, r=fmease

Add `ErrorGuaranteed` to `ast::ExprKind::Err`

See rust-lang#119967 for context
```
      \
       \
          _~^~^~_
      \) /  o o  \ (/
        '_   -   _'
        / '-----' \
```

r? fmease

src/expr.rs

@@ -404,7 +404,7 @@ pub(crate) fn format_expr(
             // These do not occur in the AST because macros aren't expanded.
             unreachable!()
         }
-        ast::ExprKind::Err => None,
+        ast::ExprKind::Err(_) | ast::ExprKind::Dummy => None,
     };
 
     expr_rw

src/utils.rs

@@ -497,7 +497,8 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         | ast::ExprKind::Break(..)
         | ast::ExprKind::Cast(..)
         | ast::ExprKind::Continue(..)
-        | ast::ExprKind::Err
+        | ast::ExprKind::Dummy
+        | ast::ExprKind::Err(_)
         | ast::ExprKind::Field(..)
         | ast::ExprKind::IncludedBytes(..)
         | ast::ExprKind::InlineAsm(..)