Disabling the package item injection routine used in the enum conversion
when there were no items to inject exposed cases where conversions would
generate duplicate declarations. The hierarchical constant and param
type conversions were trivially affected. The package conversion could
inject class items within a generate region and then re-inject them
outside of that generate region. The package conversions now uses an
upgraded generate region flattening utility to ensure injected class
items are seen. This also includes coverage for a conflict which
occurred even without the enum conversion change.