Dump and restore process with RI control block. Runtime instrumentation
allows to collect information about program execution as CPU data.

The RI control block is dumped and restored for all threads.

Ptrace kernel interface is provided by:
c122bc239b13 ("s390/ptrace: add runtime instrumention register get/set")
Signed-off-by: Alice Frosi <alice@linux.vnet.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>