Get syn tests passing with libsyntax instead of syntex
diff --git a/tests/test_generics.rs b/tests/test_generics.rs
index eda415b..69e648f 100644
--- a/tests/test_generics.rs
+++ b/tests/test_generics.rs
@@ -1,5 +1,7 @@
 #![cfg(feature = "extra-traits")]
 
+#![feature(rustc_private)]
+
 extern crate syn;
 use syn::*;