Add new d3d12_multi_wait_before_signal.py test

It's currently forcibly disabled via 'check_support' because it's known
to fail due to the fact that the commands are always serialised and
replayed in submission order instead of the order that respects queues
blocked on fence waits that get signalled later from other queues.

util/test/demos/d3d12/d3d12_multi_wait_before_signal.cpp

@@ -433,6 +433,7 @@ float4 mainPS(in float4 pos : SV_POSITION) : SV_Target0
         rootConstants[0] = 1;    // myBufferIdx
         cmd->SetGraphicsRoot32BitConstants(0, 1, &rootConstants[0], 0);
         cmd->DrawInstanced(3, 1, 3, 0);
+        setMarker(cmd, "Last draw");    // Help locate this draw through 'find_action' in python test
 
         ResourceBarrier(cmd, bbTex[texIdx], D3D12_RESOURCE_STATE_RENDER_TARGET,
                         D3D12_RESOURCE_STATE_PRESENT);

util/test/tests/D3D12/D3D12_Multi_Wait_Before_Signal.py

@@ -0,0 +1,23 @@
+import renderdoc as rd
+import rdtest
+
+class D3D12_Multi_Wait_Before_Signal(rdtest.TestCase):
+    demos_test_name = 'D3D12_Multi_Wait_Before_Signal'
+
+    def check_support(self):
+        # TODO: Enable this if/when rdoc can reorder from the original submission
+        # order, which blocks multiple queues with waits that get signalled by
+        # later submissions to other queues.
+        return False, 'Renderdoc does not yet adequately reorder capture replay'
+
+    def check_capture(self):
+        draw_marker: rd.ActionDescription = self.find_action("Last draw")
+        self.controller.SetFrameEvent(draw_marker.eventId, False)
+
+        pipe: rd.PipeState = self.controller.GetPipelineState()
+
+        tex = pipe.GetOutputTargets()[0].resourceId
+        self.check_pixel_value(tex, 270, 194, [0.20117, 0.20117, 0.20117, 0.0])
+        self.check_pixel_value(tex, 180, 170, [0.5031, 0.25, 1.0, 1.0])
+        self.check_pixel_value(tex, 180, 194, [0.25, 0.75391, 1.0, 1.0])
+