be a getter in order to enable lazily calculating the actual value when
it's needed first time. Also, a new private static member called 'memoizedDefaultLocale' is added to IntlMessageFormat to prevent
re-calculating the same defaultLocale each time it's referenced.
be a getter in order to enable lazily calculating the actual value when it's needed first time. Also, a new private static member called 'memoizedDefaultLocale' is added to IntlMessageFormat to prevent re-calculating the same defaultLocale each time it's referenced.