Make EnumFlags related code compatible with haxe-3.0
Make EnumFlags related code compatible with haxe-3.0

scriptorum/HaxePunk,MattTuttle/HaxePunk,bendmorris/HaxePunk,wselken/HaxePunk,scriptorum/HaxePunk,Pinpickle/Punkiversal,HaxePunk/HaxePunk,bendmorris/haxepop