Add test for rust-lang#67

Author: emilio

tests/expectations/type_alias_empty.rs

@@ -0,0 +1,7 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(non_snake_case)]
+
+
+

tests/headers/type_alias_empty.hpp

@@ -0,0 +1,10 @@
+// bindgen-flags: --whitelist-type bool_constant -- -std=c++11
+
+// NB: The --whitelist-type is done to trigger the traversal of the types on
+// codegen in order to trigger #67.
+
+template<typename T, T Val>
+struct integral_constant {};
+
+template<bool B>
+using bool_constant = integral_constant<bool, B>;