/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/Math/Libm/autosplit.ix is in libmath-libm-perl 1.0-1build3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # Index created by AutoSplit for blib/lib/Math/Libm.pm
# (file acts as timestamp)
1;
|