[RFC] Add IntlDateTimePatternGenerator

Hi Internals, I would like to propose an RFC https://wiki.php.net/rfc/intldatetimepatterngenerator to add IntlDateTimePatternGenerator which exposes ICU's ability to flexibly create localized date/time formatting patterns from a skeleton. Previous discussion: https://externals.io/message/113831 Implementation: https://github.com/php/php-src/pull/6771 Proposed signature: ``` class IntlDateTimePatternGenerator { public function __construct(?string $locale = null) {} public static function create(?string $locale = null): ?IntlDateTimePatternGenerator {} public function getBestPattern(string $skeleton): string|false {} } ``` There is an open question about what this should be named IntlDatePatternGenerator instead, both for brevity and to keep consistency with IntlDateFormatter. (Note that the underlying ICU classes are called DateTimePatternGenerator and DateFormatter, respectively.) I am open to switching to the shorter form. Another open question is the signature, as currently both __construct and create are exposed (like IntlDateFormatter). Other classes inside the intl extension (like IntlCalendar) only provide a static create method, and leave the __construct method private. Is there a preferred way, or are both equivalent? Regards, Mel