We are going to deprecate `WITH_RUNTIME` directive. The main reason
behind this change is that `WITH_STDLIB` directive better describes
its meaning, specifically it will add kotlin stdlib to test's classpath.
See the test added: there's a non-denotable T!! type inside flexible type
that wasn't handled before.
ConeKotlinType::contains handles flexible types content and some other cases
Also, it has better asymptotics