d3d12: Add stub for D3D12EnableExperimentalFeatures().

dlls/d3d12/d3d12.spec

@@ -6,3 +6,4 @@
 @ stub D3D12CoreRegisterLayers
 @ stdcall D3D12CreateRootSignatureDeserializer(ptr long ptr ptr)
 @ stdcall D3D12SerializeRootSignature(ptr long ptr ptr)
+@ stdcall D3D12EnableExperimentalFeatures(long ptr ptr ptr)

dlls/d3d12/d3d12_main.c

@@ -45,6 +45,15 @@ HRESULT WINAPI D3D12GetDebugInterface(REFIID iid, void **debug)
     return DXGI_ERROR_SDK_COMPONENT_MISSING;
 }
 
+HRESULT WINAPI D3D12EnableExperimentalFeatures(UINT feature_count,
+        const IID *iids, void *configurations, UINT *configurations_sizes)
+{
+    FIXME("feature_count %u, iids %p, configurations %p, configurations_sizes %p stub!\n",
+            feature_count, iids, configurations, configurations_sizes);
+
+    return E_NOINTERFACE;
+}
+
 static HRESULT d3d12_signal_event(HANDLE event)
 {
     return SetEvent(event) ? S_OK : E_FAIL;

include/d3d12.idl

@@ -2180,3 +2180,6 @@ typedef HRESULT (__stdcall *PFN_D3D12_CREATE_DEVICE)(IUnknown *adapter,
 typedef HRESULT (__stdcall *PFN_D3D12_GET_DEBUG_INTERFACE)(REFIID iid, void **debug);
 
 [local] HRESULT __stdcall D3D12GetDebugInterface(REFIID iid, void **debug);
+
+[local] HRESULT __stdcall D3D12EnableExperimentalFeatures(UINT feature_count,
+        const IID *iids, void *configurations, UINT *configurations_sizes);