vkd3d-shader/hlsl: Validate that non-uniform objects are not referenced.

Note that in the future we should call
validate_static_object_references() after DCE and pruning branches,
because shaders such as these compile (at least in more modern versions
of the native compiler):

Branch pruning:
```
static RWTexture2D<float> tex;

float4 main() : sv_target
{
    if (0)
    {
        tex[int2(0, 0)] = 2;
    }
    return 0;
}
```

DCE:
```
static Texture2D tex;
uniform uint i;

float4 main() : sv_target
{
    float4 unused = tex.Load(int3(0, 1, 2));

    return 0;
}
```

These are "todo" tests in hlsl-static-initializer.shader_test
that depend on this.

tests/object-references.shader_test

@@ -157,7 +157,7 @@ todo draw quad
 todo probe (0, 0) rgba (11.0, 12.0, 13.0, 11.0)
 
 
-[pixel shader fail todo]
+[pixel shader fail]
 float4 main(Texture2D tex2) : sv_target
 {
     Texture2D tex1;