/usr/lib/ghc-doc/hoogle/libghc-language-c-doc.txt is in libghc-language-c-doc 0.7.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-language-c-doc/html/language-c.txt