I was adapting CRIU with ia32 support for building with Koji,
and found that Koji can't build x86_64 packages and have
i686 libs installed.
While at it, I found that i686 libraries requirement is
no longer valid since I've deleted the second parasite.

Drop feature test for i686 libs and put test for gcc.
That will effectively test if gcc can compile 32-bit code
and bug with debian's gcc (#315).
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>