fix user-implementation endian

Author: zeriyoshi

ext/random/tests/engine/user_xorshift128plus.phpt

@@ -56,7 +56,7 @@ class XorShift128Plus
         $s1 ^= $s1 << 23;
         $this->s1 = $s1 ^ $s0 ^ (($s1 >> 18) & self::MASK_S18) ^ (($s0 >> 5) & self::MASK_S5);
 
-        return \pack('q*', $z);
+        return \pack('P*', $z);
     }
 
     protected function splitmix64(int &$s): int

ext/random/tests/engine/user_xoshiro128plusplus.phpt

@@ -42,7 +42,7 @@ final class Xoshiro128PP implements \Random\Engine
 
         $this->s3 = self::rotl($this->s3, 11);
 
-        return \pack('L', $result);
+        return \pack('V', $result);
     }
 }