Review: https://jetbrains.team/p/kt/reviews/7418
`State` enum contains `DISABLED` item which is redundant for
`LanguageFeature`. It's redundant because `sinceVersion = null` is used
to express the same semantic.
I had to reorder some items in the enum because otherwise
`testLanguageFeatureOrder` fails. I could keep the same logic in
`testLanguageFeatureOrder` but I would need to make
`isEnabledWithWarning` public which I don't want to. Anyway, it's not
obvious what is more readable: keep `isEnabledWithWarning = true` items
at the end or at the beginning.
Also all effectively disabled features (`sinceVersion = null` or
`defaultState = State.DISABLED`) are now moved to the "Experimental"
section at the end which is obviously better.
Nikita Bobko
cdbfcdc465