Add mkEC2LargeBuildSlave
Add mkEC2LargeBuildSlave

The kernel.org builders are throttled by the variable CPUs in
the t2.micro instances after performing a single build.  This
means that the first build takes only 20 minutes but additional
builds can take over two hours.  To keep things moving along
allow for large build slaves which will not be throttle which
are backed by spot instances.

Signed-off-by: Brian Behlendorf <32d50ad1e384dcb9a5bf7e40fa470df5dabaf348@llnl.gov>

gmelikov/zfs-buildbot,gmelikov/zfs-buildbot,zfsonlinux/zfs-buildbot,zfsonlinux/zfs-buildbot