namely, restart_mysqld_with_option.inc and kill_and_restart_mysqld.inc -
use restart_mysqld.inc instead.
Also remove innodb_wl6501_crash_stripped.inc that wasn't used anywhere.
Use include/kill_and_restart_mysqld.inc instead of triggering
DBUG_SUICIDE() with debug instrumentation. In this way, more tests
can be run with --valgrind or on non-debug servers.