• Update VirtualBox OSE to 6.1.18
• Old VirtualBox OSE 5.2.44 preserved as "-legacy" versions of the ports (repocopied)
• Add back extra patch removed in r528258, actually required to build DEBUG kmod
• Correctly define WITH_DEBUG when enabling the DEBUG option, so binaries are not stripped

Please note that this new version supports only amd64 CPUs. If you need
to use older hardware please install the legacy ports.

Note that moving VM snapshots across major updates is unsupported, it's
strongly suggested to properly shutdown VMs before upgrading, please
check UPDATING for further details.

This update is the result of work from many people, and thanks to all
who gave feedback and tested things.

Patch based on work from: Mario Lobo <lobo@bsd.com.br> and jkim.

PR: 234878
Submitted by: kunda <chitty_cloud@me.com>
Approved by: vbox (implicit)
Reviewed by: decke
Tested by: jwb,

			martin ilavsky <ilavsky.martin@gmail.com>,
			Mario Lobo <lobo@bsd.com.br>

Relnotes: https://www.virtualbox.org/wiki/Changelog-6.1
Differential Revision: https://reviews.freebsd.org/D28871