Document stat changes on DragonFly BSD

Author: rtzoeller

src/unix/bsd/freebsdlike/dragonfly/mod.rs

@@ -106,6 +106,10 @@ s! {
         pub f_uid_uuid: ::uuid_t,
     }
 
+    #[deprecated(
+        since = "0.2.107",
+        note = "stat.st_blksize is an i64 and stat.st_qspare1 is replaced with stat.st_blksize in DragonFly 5.8"
+    )]
     pub struct stat {
         pub st_ino: ::ino_t,
         pub st_nlink: ::nlink_t,