In Linux 4.11, torvalds/linux@2a1f062, signal handling related functions
were moved from sched.h into sched/signal.h.
Add configure checks to detect this and include the new file where
needed.
Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#608
9a054d54fb