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.
if it is unbound and the underlying type is reference type.
If the underlying type is primitive, it is boxed and unboxed
correctly, otherwise, it is simply casted and not unboxed.
Additionally, generate functions for inliner with inline classes
in signature, so unboxing works.
The unboxing is removed after inlining.
#KT-44722 Fixed