tests: Implement fast random on AES

Signed-off-by: Joseph Glanville <joseph.glanville@orionvm.com.au>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
shepherd: use install_crash_handler() from shepherd

The utilities related to signals provided by libsheepdog.a is also
useful for shepherd. This patch lets shepherd use it.

Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>