ext/intl: change when the locale is invalid for the 8.1/8.2 serie.

[devnexen]

does not throws an exception as it's considered as a too string change, but the code user still needs to double check.

[Girgias]

I'm not a fan, but considering this breaks BC... can you add a note in UPGRADING for 8.3 when merging upwards?

[hormus]

@Girgias please

<?php

$a = new IntlDateFormatter('C', IntlDateFormatter::FULL, IntlDateFormatter::FULL);
var_dump($a->getLocale(ULOC_VALID_LOCALE));
?>

Result:

Fatal error: Uncaught Error: Found unconstructed IntlDateFormatter in /in/qCifp:6
Stack trace:
#0 /in/qCifp(6): IntlDateFormatter->getLocale(1)
#1 {main}
  thrown in /in/qCifp on line 6

Process exited with code 255.

I would expect a notice or warning but not the fatal error. Please can you explain the usage?

[Girgias]

I do not understand ICU nor am I the maintainer of ext/intl, please file a new issue instead of responding to an old PR.