Add questasim vopt stage to have 3 step flow

[Risto97]

No description provided.

[mtravaillard]

Hi @Risto97
I have launched the CI and the dpi-c examples does not work on 3 different versions.
I am investigating a bit, seems that the problem is coming from the -sv_lib flag not being supported by vopt.
It's passed by dpi_libs_args.

edit: if i remove ${dpi_libs_args} from the elaborate cmd, it works.

[Risto97]

Yes, it was not working for me also when I tested it on bigger design.
Maybe the ${dpi_libs_args} need to be passed only to vsim but the ${hdl_libs_args} maybe should go to vopt but not vsim.

I also had an issue about it complaining aboug work lib, maybe we dont see that in our test cases as we always have unnamed library (work).

Needs more work anyways, feel free to push if you have any fixes