[php-src] Issue #7944: api to set memory_limit to "at least" this much

Issue: https://github.com/php/php-src/issues/7944 Author: divinity76 ### Description it's not rare that i see code like ini_set('memory_limit', '1G'); , where the intention is not really to set the memory limit to 1G, but to make sure that the limit is *at least* 1G, if some other code in the same script requires 4G, i don't want to overwrite that.. would be nice if there was some api kindof like ```php function memory_limit_set_at_least(int $at_least): void { $current = ini_get("memory_limit"); if ($current === "-1") { // it's already unlimited. return; } $modifier = $current[strlen($current) - 1]; $current = (int) $current; if ($modifier === "K" || $modifier === "k") { $current *= 1024; } elseif ($modifier === "M" || $modifier === "m") { $current *= 1024 * 1024; } elseif ($modifier === "G" || $modifier === "g") { $current *= 1024 * 1024 * 1024; } else { // there is no modifier. } if ($current < $at_least) { ini_set("memory_limit", (string) $at_least); } } ```