/var/lib/tex-common/fmtutil-cnf/texlive/texlive-xetex.cnf is in texlive-xetex 2015.20160320-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | xelatex xetex language.dat -etex xelatex.ini
xetex xetex language.def -etex xetex.ini
|