/usr/lib/jvm/java-8-openjdk-amd64/demo/README is in openjdk-8-demo 8u77-b03-3ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/jvm/java-8-openjdk-amd64/demo/../../../../share/doc/openjdk-8-jre-headless/demo/README