[pixel shader]
float4 main() : sv_target
{
    float4 aa = 7;
    return aa;
}

[test]
todo(msl) draw quad
probe (0, 0) rgba (7.0, 7.0, 7.0, 7.0)


[pixel shader]
float4 main() : sv_target
{
    float4 bb;
    float3 aa = 7;

    bb.xyz = aa;
    bb.w = 8.0;
    return bb;
}

[test]
todo(msl) draw quad
probe (0, 0) rgba (7.0, 7.0, 7.0, 8.0)