don't clone types that are copy

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -517,8 +517,7 @@ fn method_autoderef_steps<'tcx>(
         .by_ref()
         .map(|(ty, d)| {
             let step = CandidateStep {
-                self_ty: infcx
-                    .make_query_response_ignoring_pending_obligations(inference_vars.clone(), ty),
+                self_ty: infcx.make_query_response_ignoring_pending_obligations(inference_vars, ty),
                 autoderefs: d,
                 from_unsafe_deref: reached_raw_pointer,
                 unsize: false,

compiler/rustc_query_system/src/query/caches.rs

@@ -92,7 +92,7 @@ where
         let mut lock = self.cache.lock();
         // We may be overwriting another value. This is all right, since the dep-graph
         // will check that the fingerprint matches.
-        lock.insert(key, (value.clone(), index));
+        lock.insert(key, (value, index));
         value
     }
 
@@ -153,7 +153,7 @@ where
 
     #[inline]
     fn complete(&self, _key: (), value: V, index: DepNodeIndex) -> Self::Stored {
-        *self.cache.lock() = Some((value.clone(), index));
+        *self.cache.lock() = Some((value, index));
         value
     }
 
@@ -283,7 +283,7 @@ where
         let mut lock = self.cache.get_shard_by_hash(key.index() as u64).lock();
         #[cfg(not(parallel_compiler))]
         let mut lock = self.cache.lock();
-        lock.insert(key, (value.clone(), index));
+        lock.insert(key, (value, index));
         value
     }
 

compiler/rustc_trait_selection/src/solve/mod.rs

@@ -547,7 +547,7 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             response.value.certainty == Certainty::Yes
                 && response.has_no_inference_or_external_constraints()
         }) {
-            return Ok(response.clone());
+            return Ok(*response);
         }
 
         let certainty = candidates.iter().fold(Certainty::AMBIGUOUS, |certainty, response| {

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -599,7 +599,7 @@ fn virtual_call_violation_for_method<'tcx>(
             return false;
         }
 
-        contains_illegal_self_type_reference(tcx, trait_def_id, pred.clone())
+        contains_illegal_self_type_reference(tcx, trait_def_id, pred)
     }) {
         return Some(MethodViolationCode::WhereClauseReferencesSelf);
     }