Move DragonFly related stuff into dragonfly/*

Replicate x86_64.rs from FreeBSD. Need some twists.

Author: mneumann

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

@@ -1,3 +1,12 @@
+cfg_if! {
+    if #[cfg(target_arch = "x86_64")] {
+        mod x86_64;
+        pub use self::x86_64::*;
+    } else {
+        // ...
+    }
+}
+
 pub type fsblkcnt_t = ::c_uint;
 pub type fsfilcnt_t = ::c_uint;
 

src/unix/bsd/freebsdlike/dragonfly/x86_64.rs

@@ -0,0 +1,30 @@
+pub type c_long = i64;
+pub type c_ulong = u64;
+pub type time_t = i64;
+pub type suseconds_t = i64;
+
+s! {
+    pub struct stat {
+        pub st_dev: ::dev_t,
+        pub st_ino: ::ino_t,
+        pub st_mode: ::mode_t,
+        pub st_nlink: ::nlink_t,
+        pub st_uid: ::uid_t,
+        pub st_gid: ::gid_t,
+        pub st_rdev: ::dev_t,
+        pub st_atime: ::time_t,
+        pub st_atime_nsec: ::c_long,
+        pub st_mtime: ::time_t,
+        pub st_mtime_nsec: ::c_long,
+        pub st_ctime: ::time_t,
+        pub st_ctime_nsec: ::c_long,
+        pub st_size: ::off_t,
+        pub st_blocks: ::blkcnt_t,
+        pub st_blksize: ::blksize_t,
+        pub st_flags: ::fflags_t,
+        pub st_gen: ::uint32_t,
+        pub st_lspare: ::int32_t,
+        pub st_birthtime: ::time_t,
+        pub st_birthtime_nsec: ::c_long,
+    }
+}