Return an indexmap in all_local_trait_impls query

The data structure previously used here required Ord.
As part of #90317, we do not want DefId to implement Ord.

compiler/rustc_middle/src/query/mod.rs

@@ -1089,7 +1089,7 @@ rustc_queries! {
     }
 
     /// Return all `impl` blocks in the current crate.
-    query all_local_trait_impls(_: ()) -> &'tcx BTreeMap<DefId, Vec<LocalDefId>> {
+    query all_local_trait_impls(_: ()) -> &'tcx rustc_data_structures::fx::FxIndexMap<DefId, Vec<LocalDefId>> {
         desc { "local trait impls" }
     }