This patch add ability to test /proc/cpuinfo data
we're interested in at the moment.

The code provides the following functionality

 - cpu_init, to parse cpuinfo and check if the
   host cpu we're running on is suitable enough
   for FPU checkpoint/restore. If FPU present then
   there must be at least fxsave capability present

 - cpu_set_feature/cpu_has_feature helpers which
   provides to test certain bits and set them where
   needed (we need to set bits when parse cpuinfo)

Note, we reserve space for all cpuinfo bits known
by the kernel at moment, while use only three FPU
related bits for a while. This is done because we might
need to use or find out other features in future.

After all it's just 40 bytes of memory needed to keep
all possible bits.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>