compel: arch, x86 -- Add support of FPU restore in ia32 compat mode

To support ia32 compat mode on x86-64 we need to things

 - extend fpu_state_t type to carry ia32 specifics
 - fill up additional members in fpu_state_ia32_t type
   before calling sigreturn (this also requires the
   uc_mcontext::fpstate won't be aligned on 32 bytes)

Because we touches base types in compel the criu
has been updated accordingly.

Acked-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>