/usr/lib/ghc-doc/hoogle/simple-sendfile.txt is in libghc-simple-sendfile-doc 0.2.11-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-simple-sendfile-doc/html/simple-sendfile.txt