Unreal Engine 4 titles use AGS/NVAPI to try and enable
HDR globally.
They can key this off IDXGIOutput::GetDesc1's ColorSpace
being HDR10.
Many of these UE4 games statically link against AGS.
This is a problem as when UE4 tries to enable HDR via AGS,
it does not check if AGSContext, and the display info etc
are nullptr unlike the rest of the code using AGS.
So we need to special-case UE4 titles to disable reporting a HDR
when they are in DX11 mode.
The simplest way to do this is to key off the fact that all
UE4 titles have an executable ending with "-Win64-Shipping".
We check if d3d12.dll is present, to determine what path in
UE4 we are on, as there are some games that ship both and support HDR.
(eg. The Dark Pictures: House of Ashes, 1281590)
Luckily for us, they only load d3d12.dll on the D3D12 render path
so we can key off that to force disable HDR only in D3D11.
Add a new environment variable DXVK_ENABLE_NVAPI as an environment-level
override for 'nvapiHack'. This will allow for DLSS (and other
NvAPI-backed features) to be available without the user manually writing
a configuration file, allowing for more seamless integration with
Proton's launch script.
Some games think we are on Intel given a lack of NVAPI or AGS/atiadlxx support. Report our device memory as shared memory, and some small amount for a "carveout".
