[CRIU] [PATCH 0/18] Support descriptors sent over unix sockets (v2)

[Pavel Emelyanov]

It turned out, that the idea about all files having unique IDs was wrong,
fifos and ttys generate reg-file entry for themselves with the same ID.

Also, dgram unix sockets can be connected to self, and this wasn't handled
in unix peer resolution fixlets.

So here's the v2 with the above stuff taken into account. I've added two
patches to make fifo and tty IDs unique, fixed find_file_desc() to count
for that and tuned unix peer resolve changes to handle self-connected
dgram sockets. And rebased on recent criu-dev of course.

https://travis-ci.org/xemul/criu/builds/251242054

-- Pavel