Fix "Argument 3 ($offset) must be contained in argument 2 ($data)"

Discovered when integration-testing with the official test data from
https://github.com/google/snappy/tree/main/testdata

Author: thekid

src/main/php/io/streams/compress/Snappy.class.php

@@ -96,7 +96,7 @@ public function compress(string $data, $options= null): string {
           $hash= $next;
           $forward+= ($skip & 0xffffffff) >> 5;
           $skip++;
-          if ($pos > $limit) goto emit;
+          if ($pos > $limit || $forward > $limit) goto emit;
 
           $next= ((unpack('V', $data, $forward)[1] * self::HASH_KEY) & 0xffffffff) >> $shift;
           $candidate= $start + $hashtable[$hash];