Compare the code->name mappings we're using to the ones CLDR's
common/main/en.xml provides; report discrepancies. Tolerate tags
missing from en.xml if they're known to the locale-inheritance
machinery.
Change-Id: Ibe96c18bf55984a35de3b3644f3586a9f30720b2
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>