Skip f_reserved since size is changed

Author: JohnTitor

libc-test/build.rs

@@ -203,6 +203,8 @@ fn test_apple(target: &str) {
         match (struct_, field) {
             // FIXME: actually a union
             ("sigevent", "sigev_value") => true,
+            // FIXME: the array size has been changed since macOS 10.15 ([8] -> [7]).
+            ("statfs", "f_reserved") => true,
             _ => false,
         }
     });