zdtm: Add fd01 test

Fork tasks and create fds with different numbers.
Some children share file with parent (CLONE_FILES).
Check, than we can suspend and resume in this case.

v2: New

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>