[PATCH] d3d11/tests: Add a test for setting multiple viewports

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://testbot.winehq.org/JobDetails.pl?Key=37542

Your paranoid android.


=== wvistau64_he (32 bit d3d11) ===
d3d11.c:5340: Test failed: Got unexpected IAVertices count: 0.
d3d11.c:5341: Test failed: Got unexpected IAPrimitives count: 0.
d3d11.c:5342: Test failed: Got unexpected VSInvocations count: 0.
d3d11.c:5345: Test failed: Got unexpected CInvocations count: 0.
d3d11.c:5346: Test failed: Got unexpected CPrimitives count: 0.