code: Node createEmptyObjectLit() {
      Node result = IR.objectlit();
      if (isAddingTypes()) {
        result.setJSType(registry.createAnonymousObjectType(null));
      }
      return result;
    }
docs: Creates an empty object literal, `{}`.
  
  <p>TODO(nickreid): Consider a single method {@code createObjectLit}, which accepts varargs.
  When this method was created it seemed valuable to explicitly distinguish these cases, which is
  why this method cannot be called with args. However, that differentiation might be frustrating
  to callers.