Function call_builtin_fn 

pub fn call_builtin_fn(
    name: &str,
    tplt: Option<&[TpltParam]>,
    args: &[Instance],
    stage: ShaderStage,
) -> Result<Option<Instance>, Error>

Call a built-in function.

The arguments must be loaded.

Includes built-in constructors and zero-value constructors, except the struct zero-value constructor, since it requires knowledge of the struct type. See call_ctor or Instance::zero_value for that.

Some functions are still TODO, see call for the list of functions and statuses.