Update Linux compat version to 2.6.36

New system calls between 2.6.32 and 2.6.26 are already implemented.

This should be mostly NFC as far as contemporary Linux applications are
concerned though, as Linux kernel 3.2 is the oldest supported by a
number of popular distros today; work is in progress by others to enable
support for those applications.

Discussed with: trasz
MFC after: 1 month