/usr/lib/gcc/x86_64-linux-gnu/4.8/liblto_plugin.so is in cpp-4.8 4.8.2-19ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/gcc/x86_64-linux-gnu/4.8/liblto_plugin.so.0.0.0
/usr/lib/gcc/x86_64-linux-gnu/4.8/liblto_plugin.so.0.0.0