Re-enable warnings disabled for GCC

include/internal/catch_reenable_warnings.h

@@ -10,6 +10,8 @@
 
 #ifdef __clang__
 #pragma clang diagnostic pop
+#elif defined __GNUC__
+#pragma GCC diagnostic pop
 #endif
 
 #endif // TWOBLUECUBES_CATCH_REENABLE_WARNINGS_H_INCLUDED