function makeTileJumpBuffer(subtree) {
  const tileJumpBuffer = makeJumpBuffer(subtree._tileAvailability);
  subtree._tileJumpBuffer = tileJumpBuffer;
}
Make the jump buffer, i.e. a map of a bit index to the metadata entity ID,
for the content metadata. This is stored in the subtree.

@param {ImplicitSubtree} subtree The subtree
@private