Cleanup self-include tests to compile solely as object files

test/unordered/self_include_tests_obj.cpp

@@ -0,0 +1,9 @@
+#ifndef BOOST_UNORDERED_HEADER
+#error "this test requires a class template be passed as a macro"
+#endif
+
+#define STRINGIZE(text) STRINGIZE_I(text)
+#define STRINGIZE_I(...) #__VA_ARGS__
+
+#define HEADER STRINGIZE(BOOST_UNORDERED_HEADER)
+#include HEADER