D3D12: Added GPU based validation.
D3D12: Added GPU based validation.

jpcy/bgfx,MikePopoloski/bgfx,jdryg/bgfx,jpcy/bgfx,MikePopoloski/bgfx,jdryg/bgfx,emoon/bgfx,septag/bgfx,attilaz/bgfx,bkaradzic/bgfx,jpcy/bgfx,mendsley/bgfx,LWJGL-CI/bgfx,emoon/bgfx,jdryg/bgfx,mendsley/bgfx,jdryg/bgfx,bkaradzic/bgfx,attilaz/bgfx,fluffyfreak/bgfx,LWJGL-CI/bgfx,bkaradzic/bgfx,fluffyfreak/bgfx,septag/bgfx,emoon/bgfx,LWJGL-CI/bgfx,fluffyfreak/bgfx,mendsley/bgfx,fluffyfreak/bgfx,MikePopoloski/bgfx,bkaradzic/bgfx,LWJGL-CI/bgfx,jpcy/bgfx,septag/bgfx,attilaz/bgfx