[PATCH 6/8] d3d11/tests: Add test for staging buffers.

[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=41651

Your paranoid android.


=== wvistau64_zh_CN (32 bit Windows report) ===

d3d11:
d3d11.c:5562: Test failed: Got unexpected IAVertices count: 0.
d3d11.c:5563: Test failed: Got unexpected IAPrimitives count: 0.
d3d11.c:5564: Test failed: Got unexpected VSInvocations count: 0.
d3d11.c:5567: Test failed: Got unexpected CInvocations count: 0.
d3d11.c:5568: Test failed: Got unexpected CPrimitives count: 0.

=== w2008s64 (32 bit Windows report) ===

d3d11:
d3d11.c:5562: Test failed: Got unexpected IAVertices count: 0.
d3d11.c:5563: Test failed: Got unexpected IAPrimitives count: 0.
d3d11.c:5564: Test failed: Got unexpected VSInvocations count: 0.
d3d11.c:5567: Test failed: Got unexpected CInvocations count: 0.
d3d11.c:5568: Test failed: Got unexpected CPrimitives count: 0.