Define the behavior of AvoidAsyncVoid for event handlers

[sharwell]

Currently the AvoidAsyncVoid analyzer does not have any special consideration for event handlers. The desired behavior for these cases should be explicitly documented, even if the implementation is kept as-is.

[paulomorgado]

@sharwell, I don't understand what you mean. Do you mean that this should be reported for event handlers and explicitly ignored?

[sharwell]

@paulomorgado I'm saying we should do one of the following:

1. Keep the code as-is, but add documentation (using async void reports a diagnostic even if it's an event handler)
2. Modify the code so async void event handlers are allowed and document it

[JohanLarsson]

Related: #53

[paulomorgado]

@sharwell, I'm sorry but I'm still not getting it.

By "modify the code" do you mean adding #pragma directives?

[sharwell]

@paulomorgado No, I mean modify the way this analyzer examines code. Right now there is no special analysis for event handlers so they are analyzed the same way as any other method.

[paulomorgado]

Oh! I thought you're saying something else.