vkd3d-shader/hlsl: Parse state block entries function call syntax.

Allows the parsing of state block entries using the function syntax (in contrast to the assignment syntax which is already upstream).

The next step is parsing the compile and CompileShader() syntaxes to allow parsing expressions such as these:

technique10 T0
{
    pass P0
    {
        SetPixelShader(CompileShader(ps_4_0, function(arg)));
    }
}