Re: [PATCH 0/2] MR184: Draft: vkd3d-shader/hlsl: Add support for SampleGrad() method

[Ethan Lee (＠flibitijibibo)]

Pushed it a little bit harder and got it to compile this:

```
Texture2D t;
SamplerState s;

float4 dd;

float4 main(float4 position : SV_POSITION) : SV_Target
{
    float2 p;

p.x = position.x / 640.0f;
    p.y = position.y / 480.0f;
    float2 ddx = dd.xy / float2(1, 1);
    float2 ddy = dd.zw / float2(1, 1);
    return t.SampleGrad(s, p, ddx, ddy);
}
```

This just makes it so the compiler is forced to make a temp register for ddx/ddy, and that makes it happy. So temp registers work too... so why might load instructions be fussy with these last two parameters?