For now only effective in the DISABLE_DYNLOADING case, where it limits
the locales compiled in to the i18npool library. Maybe should use this
same option to also limit what collation tables etc are compiled in?

Not expected to be used for desktop OSes, but can be useful for mobile
platforms where every megabyte counts.

Change-Id: If672b4cd19f44f8c7e119378faf40930a51969b7