[d3d11] Zero-initialize UAV counters

Fixes a hang in Dirt Rally on RADV.

src/d3d11/d3d11_device.cpp

@@ -427,7 +427,9 @@ namespace dxvk {
       return S_FALSE;
     
     try {
-      *ppUAView = ref(new D3D11UnorderedAccessView(this, pResource, &desc));
+      auto uav = new D3D11UnorderedAccessView(this, pResource, &desc);
+      m_initializer->InitUavCounter(uav);
+      *ppUAView = ref(uav);
       return S_OK;
     } catch (const DxvkError& e) {
       Logger::err(e.message());

src/d3d11/d3d11_initializer.cpp

@@ -47,6 +47,24 @@ namespace dxvk {
   }
 
 
+  void D3D11Initializer::InitUavCounter(
+          D3D11UnorderedAccessView*   pUav) {
+    auto counterBuffer = pUav->GetCounterSlice();
+
+    if (!counterBuffer.defined())
+      return;
+
+    std::lock_guard<std::mutex> lock(m_mutex);
+
+    const uint32_t zero = 0;
+    m_context->updateBuffer(
+      counterBuffer.buffer(),
+      0, sizeof(zero), &zero);
+
+    FlushImplicit();
+  }
+
+
   void D3D11Initializer::InitDeviceLocalBuffer(
           D3D11Buffer*                pBuffer,
     const D3D11_SUBRESOURCE_DATA*     pInitialData) {

src/d3d11/d3d11_initializer.h

@@ -35,6 +35,9 @@ namespace dxvk {
             D3D11CommonTexture*         pTexture,
       const D3D11_SUBRESOURCE_DATA*     pInitialData);
 
+    void InitUavCounter(
+            D3D11UnorderedAccessView*   pUav);
+    
   private:
 
     std::mutex        m_mutex;