I'll bet $3 these were maybe extracted from Microsoft Symbol Server. Note it's not a MSFT site, it's some training firm.
This is not a file dump, but a file directory listing where he reproduces something Mark Russinovich did a while ago.
See also his tweet here:
https://twitter.com/aionescu/status/547322576947523586
quote: I've built an entire mapping of the Windows 10 Source Tree, similar to what @markrussinovich did back in the days