message: Rafs: add socket file support
  Given OCI image spec supports sock file, lets stick to it.
diff: @@ -1141,8 +1141,14 @@ impl InodeWrapper {
  }
  }
  + pub fn is_sock(&self) -> bool {
  + match self {
  + InodeWrapper::V5(i) => i.i_mode & libc::S_IFMT == libc::S_IFSOCK,
  + }
  + }
  +
  pub fn is_special(&self) -> bool {
  - self.is_chrdev() || self.is_blkdev() || self.is_fifo()
  + self.is_chrdev() || self.is_blkdev() || self.is_fifo() || self.is_sock()
  }
  pub fn has_xattr(&self) -> bool {
  