Library methods such as 'listOf' are resolved
to have the package fragments as their parents,
but JVM expects their containing file classes as parents.
This fix generates those file classes and
uses them as parent replacements for such library methods.
unsigned ranges/progressions.
The tests pass in JVM_IR for signed, but fail for unsigned due to
inlining being broken. We can disable the JVM_IR tests for unsigned,
while keeping them enabled for signed, to get better test coverage in
the interim until inlining is fixed.