/usr/lib/ghc-doc/hoogle/pcre-light.txt is in libghc-pcre-light-doc 0.4-6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-pcre-light-doc/html/pcre-light.txt