dawn-cmake/test/tint/buffer/uniform/std140/mat4x2/to_private.wgsl

struct S {
  before : i32,
  m : mat4x2<f32>,
  after : i32,
}

@group(0) @binding(0) var<uniform> u : array<S, 4>;
var<private> p : array<S, 4>;

@compute @workgroup_size(1)
fn f() {
    p = u;
    p[1] = u[2];
    p[3].m = u[2].m;
    p[1].m[0] = u[0].m[1].yx;
}