In the newly added test, prior to this change, JVM IR was generating
DefaultImpls classes with calls to things like
`kotlin/collections/MutableList$DefaultImpls.spliterator` and other
default methods present in JDK 8+. This obviously didn't make much
sense. Although these weren't explicitly mentioned anywhere in the
bytecode, they caused some validation tools to report errors (e.g.
animalsniffer used in arrow).
Alexander Udalov
5647a935a2