Rollup merge of #100221 - compiler-errors:impossible-trait-items, r=lcnr,notriddle,camelid

Don't document impossible to call default trait items on impls

Closes #100176

This only skips documenting _default_ trait items on impls, not ones that are written inside the impl block. This is a conservative approach, since I think we should document all items written in an impl block (I guess unless hidden or whatever), but the existence of this new query I added makes this easy to extend to other rustdoc cases.

compiler/rustc_middle/src/query/mod.rs

@@ -1956,6 +1956,14 @@ rustc_queries! {
         }
     }
 
+    query is_impossible_method(key: (DefId, DefId)) -> bool {
+        desc { |tcx|
+            "checking if {} is impossible to call within {}",
+            tcx.def_path_str(key.1),
+            tcx.def_path_str(key.0),
+        }
+    }
+
     query method_autoderef_steps(
         goal: CanonicalTyGoal<'tcx>
     ) -> MethodAutoderefStepsResult<'tcx> {