This catches when a client creates an action and discards it, thinking that the action has actually been applied to something.
This will help people who make the mistake of defining, for example, both `void Use(Foo*, Bar)` and `ACTION_P(Use, bar) { Use(arg, bar); }` for later application to a Foo. With such an overload, a client may then write `Use(bar);`, selecting the Action<> overload and being confused why nothing happens.
This also catches when a client defines their own action in terms of an ACTION_P()-generated one, invokes the Action<>'s builder, and then fails to invoke the resulting action, thinking it's operating on the outer action's parameters.
PiperOrigin-RevId: 433197479
Change-Id: I98e4389150d01a5e753230113016d9fc38b1d260
ae1b7ad430