.. which prepares us for handling of discontinuous functions. The main
change there is that we can have multiple FDEs contributing towards an
unwind plan of a single function. This patch separates the logic for
parsing of a single FDE from the construction of an UnwindPlan (so that
another patch can change the latter to combine several unwind plans).
Co-authored-by: Jonas Devlieghere <jonas@devlieghere.com>