[intl] Preserve PHP-side state when cloning formatters

[iliaal]

Cloning IntlDateFormatter left dateType, timeType, calendar, and the requested locale at constructor defaults, and cloning MessageFormatter dropped its pattern. The clone handlers now copy those PHP-side fields with the ICU handle.

[LamentXU123]

I'd suggest to add this test

<?php
$m = new MessageFormatter('en_US', '{0,number} | {1,time,short} | {2,date,medium}');
$dt = new DateTimeImmutable('2026-01-02 03:04:05', new DateTimeZone('UTC'));
$m->format([1, $dt, $dt]);
$mc = clone $m;
$original = $m->format([1, $dt, $dt]);
$cloned = $mc->format([1, $dt, $dt]);
var_dump($mc->getPattern());
var_dump($original === $cloned);
?>

Otherwise this looks good to me.

[LamentXU123]

Otherwise looks good.

[LamentXU123]

nit: no need for new empty lines.

[iliaal]

Ran it on unpatched 8.4: getPattern() goes red, but $original === $cloned is already true there, so only the pattern half discriminates and the existing case covers that. Changing the default timezone between the two format() calls does discriminate, so I added that instead: without the tz_set copy the clone re-adopts the current zone and diverges from the original.