s390x: Add specification exception interception test

Check that specification exceptions cause intercepts when
specification exception interpretation is off.
Check that specification exceptions caused by program new PSWs
cause interceptions.
We cannot assert that non program new PSW specification exceptions
are interpreted because whether interpretation occurs or not is
configuration dependent.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20211022131057.1308851-2-scgl@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>