Remove useless bounds.

Author: cjgillot

compiler/rustc_query_system/src/dep_graph/dep_node.rs

@@ -50,7 +50,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use std::fmt;
 use std::hash::Hash;
 
-#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable)]
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct DepNode<K> {
     pub kind: K,
     pub hash: PackedFingerprint,

compiler/rustc_query_system/src/dep_graph/serialized.rs

@@ -258,7 +258,7 @@ impl<K: DepKind> EncoderState<K> {
     }
 }
 
-#[derive(Debug, Encodable, Decodable)]
+#[derive(Debug)]
 pub struct NodeInfo<K: DepKind> {
     node: DepNode<K>,
     fingerprint: Fingerprint,