function updateClippingPolygons(tile, tileset) {
  const clippingPolygons = tileset.clippingPolygons;
  let currentClippingPolygonsState = 0;
  if (
    defined(clippingPolygons) &&
    tile._isClippedByPolygon &&
    clippingPolygons.enabled
  ) {
    currentClippingPolygonsState = clippingPolygons.clippingPolygonsState;
  }
  // If clippingPolygonState for tile changed, mark clippingPolygonsDirty so content can update
  if (currentClippingPolygonsState !== tile._clippingPolygonsState) {
    tile._clippingPolygonsState = currentClippingPolygonsState;
    tile.clippingPolygonsDirty = true;
  }
}
Compute and compare ClippingPolygons state:
 - enabled-ness - are clipping polygons enabled? is this tile clipped?
 - clipping polygon count & position count
 - clipping function (inverse)
@private
@param {Cesium3DTile} tile
@param {Cesium3DTileset} tileset