Always encode implied_predicates query for traits

With associated type bounds enabled, the implied_predicates and super_predicates
queries may differ for traits, since associated type bounds are also
implied but are not counted as super predicates.

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -211,6 +211,7 @@ provide! { tcx, def_id, other, cdata,
     generics_of => { table }
     inferred_outlives_of => { table_defaulted_array }
     super_predicates_of => { table }
+    implied_predicates_of => { table }
     type_of => { table }
     type_alias_is_lazy => { cdata.root.tables.type_alias_is_lazy.get(cdata, def_id.index) }
     variances_of => { table }
@@ -276,18 +277,6 @@ provide! { tcx, def_id, other, cdata,
             .map(|lazy| lazy.decode((cdata, tcx)))
             .process_decoded(tcx, || panic!("{def_id:?} does not have trait_impl_trait_tys")))
     }
-    implied_predicates_of => {
-        cdata
-            .root
-            .tables
-            .implied_predicates_of
-            .get(cdata, def_id.index)
-            .map(|lazy| lazy.decode((cdata, tcx)))
-            .unwrap_or_else(|| {
-                debug_assert_eq!(tcx.def_kind(def_id), DefKind::Trait);
-                tcx.super_predicates_of(def_id)
-            })
-    }
 
     associated_types_for_impl_traits_in_associated_fn => { table_defaulted_array }
 

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1435,6 +1435,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             if let DefKind::Trait = def_kind {
                 record!(self.tables.trait_def[def_id] <- self.tcx.trait_def(def_id));
                 record!(self.tables.super_predicates_of[def_id] <- self.tcx.super_predicates_of(def_id));
+                record!(self.tables.implied_predicates_of[def_id] <- self.tcx.implied_predicates_of(def_id));
 
                 let module_children = self.tcx.module_children_local(local_id);
                 record_array!(self.tables.module_children_non_reexports[def_id] <-

tests/ui/associated-type-bounds/implied-predicates.rs

@@ -1,4 +1,5 @@
 //@ aux-build:implied-predicates.rs
+//@ check-pass
 
 extern crate implied_predicates;
 use implied_predicates::Bar;