Support cfg_attr_trace

Author: GuillaumeGomez

src/librustdoc/clean/types.rs

@@ -1101,7 +1101,7 @@ pub(crate) fn extract_cfg_from_attrs<'a, I: Iterator<Item = &'a hir::Attribute>
     'main: for attr in attrs {
         let Some(ident) = attr.ident() else { continue };
         match ident.name {
-            sym::cfg if enable_auto_cfg => {
+            sym::cfg | sym::cfg_attr_trace if enable_auto_cfg => {
                 if let Some(attr) = single(attr.meta_item_list()?)
                     && let Some(new_cfg) =
                         Cfg::parse_without(attr.meta_item()?, &cfg_info.hidden_cfg).ok().flatten()