Representation of an event trigger.
This is a product type, introduced by deftagsum in support of vl-stmt.
Event trigger statements are used to explicitly trigger named events. They are discussed in Section 9.7.3 and looks like this:
-> foo; -> bar[1][2][3]; // I think?
BOZO are we handling the syntax correctly? What about the
expressions that can follow the trigger? Maybe they just become part of the