function bindSelf(env, scope, self) {
  scope.self = self;
}
Host Hook: bindSelf

  @param {Scope} scope
  @param {any} self

  Corresponds to entering a template.

  This hook is invoked when the `self` value for a scope is ready to be bound.

  The host must ensure that child scopes reflect the change to the `self` in
  future calls to the `get` hook.