DateFormat crashes for unsupported locale "cnr_ME" instead of falling back #1004
Description
When using intl.DateFormat in Flutter/Dart with the locale "cnr_ME" (Montenegrin), the formatter throws an error because the locale is not supported in intl’s locale tables.
On Android native (ICU/libcore), unsupported locales gracefully fallback:
"cnr_ME" → "sr_ME" → "sr" → "en"
But in Flutter’s intl package, the fallback is missing and it crashes.
This breaks apps when the device language/region is set to "cnr_ME".
Expected Behavior
intl should fallback like Android’s ICU/libcore:
If "cnr_ME" is unsupported, try "sr_ME", then "sr", then "en".
Actual Behavior
intl throws:
FormatException: Locale data has not been initialized for locale cnr_ME.