dawn-cmake/test/builtins/textureGather/f32/red.wgsl

@group(1) @binding(0) var t : texture_2d<f32>;
@group(1) @binding(1) var s : sampler;

@stage(fragment)
fn main() {
  var res : vec4<f32> = textureGather(0, t, s, vec2<f32>());
}