It does use them in a few places. See for example:...

# coroutines

[elizarov]

It does use them in a few places. See for example: https://github.com/JetBrains/kotlin/blob/8fc953f529b72aaa137b9615e825f8021cbeb8ca/compiler/frontend/src/org/jetbrains/kotlin/analyzer/AnalyzerFacade.kt#L186