I found this file, and it was NOT there in 5.0, so I'm wondering what it's used for now, (5.1.1), and why it's separated from the standard shader. From what I can tell it's supposed to render the reflection probes into a separate texture, then use that to later add to the lighting buffer. When looking at unity's roadmap such a feature claims to be planned for 5.2, but is it already in use? Or is the file simply there?