/usr/lib/x86_64-linux-gnu/perl5/ is in libforks-perl 0.36-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/perl5/5.20/
/usr/lib/x86_64-linux-gnu/perl5/5.20/auto/
/usr/lib/x86_64-linux-gnu/perl5/5.20/auto/forks/
/usr/lib/x86_64-linux-gnu/perl5/5.20/auto/forks/forks.so
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/Devel/
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/Devel/Symdump.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/shared/
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/shared.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/shared/attributes.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/shared/global_filter.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/forks/signals.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/threads/
/usr/lib/x86_64-linux-gnu/perl5/5.20/threads/shared/
/usr/lib/x86_64-linux-gnu/perl5/5.20/threads/shared/array.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/threads/shared/handle.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/threads/shared/hash.pm
/usr/lib/x86_64-linux-gnu/perl5/5.20/threads/shared/scalar.pm