Most of these tests used this directive as a way to opt in to a new
language feature, and most of those features are already stable for a
long time, so no opt-in is needed. Some other tests used the directive
to opt out from a language feature, replace those by the `LANGUAGE`
directive. One test used the directive to test behavior that actually
depended on the API version; use `API_VERSION` directive there instead.
The implementation is a bit obscure because this worked on JS since
Kotlin 1.0 and we should not break that; however, on JVM, a diagnostic
will be reported with old language/API version
#KT-25241 Fixed
This patch mutes the following test categories:
* Tests with java dependencies (System class,
java stdlib, jvm-oriented annotations etc).
* Coroutines tests.
* Reflection tests.
* Tests with an inheritance from the standard
collections.
Alexander Udalov