statx(2) allows nullptr for the path now.

The behavior changed with https://github.com/torvalds/linux/commit/0ef625bba6fb2bc0c8ed2aab9524fdf423f67dd5.

Change-Id: Id16f6741f0dc8c1f0f960d063212a1a85c849dca
diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index bb188fe..2633b69 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -331,7 +331,7 @@
  *
  * Available since API level 30.
  */
-int statx(int __dir_fd, const char* _Nonnull __path, int __flags, unsigned __mask, struct statx* _Nonnull __buf) __INTRODUCED_IN(30);
+int statx(int __dir_fd, const char* _Nullable __path, int __flags, unsigned __mask, struct statx* _Nonnull __buf) __INTRODUCED_IN(30);
 #endif
 
 __END_DECLS