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.
We get the info for the underlying progression and invert it. For
progressions whose last bound was open (e.g., `until` loop), the
reversed version will have an open first bound and so the induction
variable must be incremented first.
Also unified the way of extracting HeaderInfo out of changed calls
(e.g., `indices.reversed()`), and fixed declaration parents in
ForLoopsLowering.