Re: [PATCH v4 0/2] MR2045: d3d12core: Add stub DLL.

[Mohamad Al-Jaf (＠maljaf)]

v4
- Add DirectX 12 Agility SDK defintions.
- Recode D3D12SDKVersion as a variable.
- Add basic test for D3D12GetInterface.
- Return correct HRESULT from D3D12GetInterface upon failure.