virtual interface support

[jrudess]

I see that virtual interfaces are listed as only partially supported. Can you describe what is currently supported?

For reference, here's the errors given when declaring a virtual interface within a class:

monitor.svh:31:15: error: invalid property qualifier 'virtual'
    protected virtual my_intf _bus;
              ^~~~~~~
monitor.svh:31:23: error: 'my_intf' is an interface definition but is used like a type
    protected virtual my_intf _bus;
                      ^~~~~~~

[MikePopoloski]

The basics of a virtual interface as a data type are supported; see the "Virtual interface data type" unit test for examples. The error you posted looks like a simple parser bug, probably confused by the protected keyword prior to it.

I don't remember exactly what I knew was missing; I'd have to go back through that section of the LRM and check each feature and restriction and make sure they're all implemented.

[jrudess]

No worries on details. I just didn't want to start submitting issues for things already known to not be implemented.