Make is_object_safe a method.

src/librustc/query/mod.rs

@@ -653,9 +653,6 @@ rustc_queries! {
             desc { |tcx| "building specialization graph of trait `{}`", tcx.def_path_str(key) }
             cache_on_disk_if { true }
         }
-        query is_object_safe(key: DefId) -> bool {
-            desc { |tcx| "determine object safety of trait `{}`", tcx.def_path_str(key) }
-        }
         query object_safety_violations(key: DefId) -> Vec<traits::ObjectSafetyViolation> {
             desc { |tcx| "determine object safety of trait `{}`", tcx.def_path_str(key) }
         }

src/librustc/ty/mod.rs

@@ -2998,6 +2998,10 @@ impl<'tcx> TyCtxt<'tcx> {
         };
         (ident, scope)
     }
+
+    pub fn is_object_safe(self, key: DefId) -> bool {
+        self.object_safety_violations(key).is_empty()
+    }
 }
 
 #[derive(Clone, HashStable)]

src/librustc_incremental/persist/dirty_clean.rs

@@ -78,7 +78,7 @@ const BASE_STRUCT: &[&str] =
 const BASE_TRAIT_DEF: &[&str] = &[
     label_strs::associated_item_def_ids,
     label_strs::generics_of,
-    label_strs::is_object_safe,
+    label_strs::object_safety_violations,
     label_strs::predicates_of,
     label_strs::specialization_graph_of,
     label_strs::trait_def,

src/librustc_infer/traits/object_safety.rs

@@ -772,10 +772,6 @@ fn contains_illegal_self_type_reference<'tcx>(
     error
 }
 
-fn is_object_safe(tcx: TyCtxt<'_>, trait_def_id: DefId) -> bool {
-    tcx.object_safety_violations(trait_def_id).is_empty()
-}
-
 pub fn provide(providers: &mut ty::query::Providers<'_>) {
-    *providers = ty::query::Providers { is_object_safe, object_safety_violations, ..*providers };
+    *providers = ty::query::Providers { object_safety_violations, ..*providers };
 }