Process: split getMemoryUsage() into 2 functions

this isn't released yet so it's OK to change.
phpstan level 7 doesn't like these kinds of ambiguous return types because there's no way for it to tell which type is returned without a return type specifying extension, and it's easier to just change the API than to make PHPStan understand it.

src/pocketmine/MemoryManager.php

@@ -226,7 +226,7 @@ class MemoryManager{
 
 		if(($this->memoryLimit > 0 or $this->globalMemoryLimit > 0) and ++$this->checkTicker >= $this->checkRate){
 			$this->checkTicker = 0;
-			$memory = Process::getMemoryUsage(true);
+			$memory = Process::getAdvancedMemoryUsage();
 			$trigger = false;
 			if($this->memoryLimit > 0 and $memory[0] > $this->memoryLimit){
 				$trigger = 0;

src/pocketmine/Server.php

@@ -2325,7 +2325,7 @@ class Server{
 		Timings::$titleTickTimer->startTiming();
 		$d = Process::getRealMemoryUsage();
 
-		$u = Process::getMemoryUsage(true);
+		$u = Process::getAdvancedMemoryUsage();
 		$usage = sprintf("%g/%g/%g/%g MB @ %d threads", round(($u[0] / 1024) / 1024, 2), round(($d[0] / 1024) / 1024, 2), round(($u[1] / 1024) / 1024, 2), round(($u[2] / 1024) / 1024, 2), Process::getThreadCount());
 
 		echo "\x1b]0;" . $this->getName() . " " .

src/pocketmine/command/defaults/StatusCommand.php

@@ -49,7 +49,7 @@ class StatusCommand extends VanillaCommand{
 		}
 
 		$rUsage = Process::getRealMemoryUsage();
-		$mUsage = Process::getMemoryUsage(true);
+		$mUsage = Process::getAdvancedMemoryUsage();
 
 		$server = $sender->getServer();
 		$sender->sendMessage(TextFormat::GREEN . "---- " . TextFormat::WHITE . "Server status" . TextFormat::GREEN . " ----");

src/pocketmine/event/server/LowMemoryEvent.php

@@ -75,6 +75,7 @@ class LowMemoryEvent extends ServerEvent{
 	 * Amount of memory already freed
 	 */
 	public function getMemoryFreed() : int{
-		return $this->getMemory() - ($this->isGlobal() ? Process::getMemoryUsage(true)[1] : Process::getMemoryUsage(true)[0]);
+		$usage = Process::getAdvancedMemoryUsage();
+		return $this->getMemory() - ($this->isGlobal() ? $usage[1] : $usage[0]);
 	}
 }

src/pocketmine/scheduler/SendUsageTask.php

@@ -136,7 +136,7 @@ class SendUsageTask extends AsyncTask{
 					"historyList" => array_values($playerList)
 				];
 
-				$info = Process::getMemoryUsage(true);
+				$info = Process::getAdvancedMemoryUsage();
 				$data["system"] = [
 					"mainMemory" => $info[0],
 					"totalMemory" => $info[1],

src/pocketmine/utils/Process.php

@@ -47,9 +47,10 @@ final class Process{
 	}
 
 	/**
-	 * @return int[]|int
+	 * @return int[]
+	 * @phpstan-return array{int,int,int}
 	 */
-	public static function getMemoryUsage(bool $advanced = false){
+	public static function getAdvancedMemoryUsage(){
 		$reserved = memory_get_usage();
 		$VmSize = null;
 		$VmRSS = null;
@@ -70,10 +71,6 @@ final class Process{
 			$VmRSS = memory_get_usage();
 		}
 
-		if(!$advanced){
-			return $VmRSS;
-		}
-
 		if($VmSize === null){
 			$VmSize = memory_get_usage(true);
 		}
@@ -81,6 +78,10 @@ final class Process{
 		return [$reserved, $VmRSS, $VmSize];
 	}
 
+	public static function getMemoryUsage() : int{
+		return self::getAdvancedMemoryUsage()[1];
+	}
+
 	/**
 	 * @return int[]
 	 */

src/pocketmine/utils/Utils.php

@@ -283,11 +283,12 @@ class Utils{
 	/**
 	 * @deprecated
 	 * @see Process::getMemoryUsage()
+	 * @see Process::getAdvancedMemoryUsage()
 	 *
 	 * @return int[]|int
 	 */
 	public static function getMemoryUsage(bool $advanced = false){
-		return Process::getMemoryUsage($advanced);
+		return $advanced ? Process::getAdvancedMemoryUsage() : Process::getMemoryUsage();
 	}
 
 	/**