dawn-cmake/test/shader_io/fragment_input_builtins.wgsl

[[stage(fragment)]]
fn main(
  [[builtin(position)]] position : vec4<f32>,
  [[builtin(front_facing)]] front_facing : bool,
  [[builtin(sample_index)]] sample_index : u32,
  [[builtin(sample_mask)]] sample_mask : u32,
) {
  if (front_facing) {
    let foo : vec4<f32> = position;
    let bar : u32 = sample_index + sample_mask;
  }
}