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.
Put their content to constructor-impl, so they are called during
constructor call, but they are not called during boxing, because
box-impl calls <init> and not constructor-impl.
#KT-28055 In progress