CC: @iritkatriel

Issue GH-89874 gets rid of exception triples where it makes sense. I don't know if it was considered, but another place where such triples are supported is the gen.throw(). It allows passing either an exception, or a (type, value, traceback) triple where the value and traceback are optional. I think it makes sense to keep allowing passing an exception type, but I don't see the use case for passing separate type and value. We could deprecate this easily by adding a warning to gen_throw() when more than one argument is present.

Thoughts?