In my magento root folder under var/package/ I can see all the xml files for all the magento versions I've ever had. Here's an example of what I'm seeing.
Cm_RedisSession-1.8.0.0.xml 1.17 KB 0755
Cm_RedisSession-1.9.2.0.xml 1.17 KB 0644
Cm_RedisSession-1.9.2.1.xml 1.17 KB 0644
Cm_RedisSession-1.9.2.2.xml 1.17 KB 0644
Is it safe to delete these files up to my current version 1.9.2.2?