Rename non-Ident fields previously named ident

It will be clearer to avoid using 'ident' to refer to anything but Ident.
diff --git a/syntax/mangle.rs b/syntax/mangle.rs
index 55ffca5..cc5115a 100644
--- a/syntax/mangle.rs
+++ b/syntax/mangle.rs
@@ -15,13 +15,13 @@
         Some(receiver) => {
             let receiver_ident = types.resolve(&receiver.ty);
             join!(
-                efn.ident.namespace,
+                efn.name.namespace,
                 CXXBRIDGE,
                 receiver_ident.cxx,
-                efn.ident.rust
+                efn.name.rust
             )
         }
-        None => join!(efn.ident.namespace, CXXBRIDGE, efn.ident.rust),
+        None => join!(efn.name.namespace, CXXBRIDGE, efn.name.rust),
     }
 }