/usr/lib/x86_64-linux-gnu/ is in libgtk2-spell-perl 1.04-3build2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/perl5/
/usr/lib/x86_64-linux-gnu/perl5/5.26/
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/Spell/
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/Spell/Install/
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/Spell/Install/Files.pm
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/Spell/Install/gtk2spellperl.h
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/Spell/Install/gtkspell.typemap
/usr/lib/x86_64-linux-gnu/perl5/5.26/Gtk2/Spell.pm
/usr/lib/x86_64-linux-gnu/perl5/5.26/auto/
/usr/lib/x86_64-linux-gnu/perl5/5.26/auto/Gtk2/
/usr/lib/x86_64-linux-gnu/perl5/5.26/auto/Gtk2/Spell/
/usr/lib/x86_64-linux-gnu/perl5/5.26/auto/Gtk2/Spell/Spell.so