How to use the @glimmer/vm.Register.s0 function in @glimmer/vm

CLIENT_SIDE.add(ClientSide.Ops.DidCreateElement, (_sexp: ClientSide.DidCreateElement, builder: OpcodeBuilder) => {
  builder.didCreateElement(Register.s0);
});

(_sexp: ClientSide.DidRenderLayout, builder: OpcodeBuilder) => {
      builder.didRenderLayout(Register.s0);
    }
  );

(_sexp: ClientSide.DidCreateElement, builder: OpcodeBuilder) => {
      builder.didCreateElement(Register.s0);
    }
  );

STATEMENTS.add(Ops.AttrSplat, (sexp: WireFormat.Statements.AttrSplat, builder: OpcodeBuilder) => {
  let [, to] = sexp;

  builder.yield(to, []);
  builder.didCreateElement(Register.s0);
  builder.setComponentAttrs(false);
});