Use case

I wanted to implement a grid showing all possible icons on the Icons class, so my user could choose one.

Proposal

I found out that the Icons class is not an enum and therefore has no values property. Since now we have enhanced enums (from dart-lang/sdk/#47849), I believe this change could possibly be made. I'm not sure how that would impact on the already existing features that use it. I know all the actual icons are IconData objects, but maybe something could be done to make this change easier?