Skip test which is 64bits only

Diff from test output
001+ Warning: fread(): Length parameter must be greater than 0 in ...
001- Warning: fread(): Length parameter must be no more than 2147483647 in ...

Author: remicollet

ext/standard/tests/file/bug72114.phpt

@@ -1,5 +1,7 @@
 --TEST--
 Bug #72114 (Integer underflow / arbitrary null write in fread/gzread)
+--SKIPIF--
+<?php if (PHP_INT_SIZE != 8) die("skip this test is for 64bit platform only"); ?>
 --FILE--
 <?php
 ini_set('memory_limit', "2500M");