/etc/jetty8/contexts/solr.xml is in solr-jetty 3.6.2+dfsg-5+deb8u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/jetty8/contexts/../../solr/solr-jetty.xml
/etc/jetty8/contexts/../../solr/solr-jetty.xml