test/intrinsics/textureGather/f32/alpha.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(3, t, s, vec2<f32>());
}