The CDS APIs have some excessively long names:

    HeapShared::set_closed_archive_heap_region_mapped()
    HeapShared::fixup_mapped_heap_regions()
    MetaspaceShared::first_closed_archive_heap_region
    FileMapInfo::write_archive_heap_regions()

Words such as "archive_heap_", "archive_", "heap_", ... can be removed when the context is clear:

    HeapShared::set_closed_regions_mapped()
    HeapShared::fixup_mapped_regions()
    MetaspaceShared::first_closed_heap_region
    FileMapInfo::write_heap_regions()

This RFE also fixes some irregularities and grammatical errors in the code:

[1] GrowableArray<MemRegion>* {archive, mem, range}
     =>
     GrowableArray<MemRegion>* regions

[2] The word "region" is changed to "regions" when appropriate

[3] Remove unused HeapShared::_archive_heap_region_fixed