Derive HashStable_Generic for Ident.

Author: cjgillot

src/librustc/ich/impls_hir.rs

@@ -161,11 +161,6 @@ impl<'a> HashStable<StableHashingContext<'a>> for hir::Expr {
 
 impl_stable_hash_for_spanned!(usize);
 
-impl_stable_hash_for!(struct ast::Ident {
-    name,
-    span,
-});
-
 impl<'a> HashStable<StableHashingContext<'a>> for hir::TraitItem {
     fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
         let hir::TraitItem {

src/libsyntax_pos/symbol.rs

@@ -5,7 +5,7 @@
 use arena::DroplessArena;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_index::vec::Idx;
-use rustc_macros::symbols;
+use rustc_macros::{symbols, HashStable_Generic};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 use rustc_serialize::{UseSpecializedDecodable, UseSpecializedEncodable};
 use rustc_data_structures::stable_hasher::{HashStable, ToStableHashKey, StableHasher};
@@ -752,7 +752,7 @@ symbols! {
     }
 }
 
-#[derive(Copy, Clone, Eq)]
+#[derive(Copy, Clone, Eq, HashStable_Generic)]
 pub struct Ident {
     pub name: Symbol,
     pub span: Span,