Mark test as XFAIL due to wrong assumptions

Author: derickr

ext/intl/tests/dateformat_format_variant3.phpt

@@ -1,5 +1,7 @@
 --TEST--
 datefmt_format_code()
+--XFAIL--
+This test assumes wrong data wrt to PDT. It is also too big and needs splitting up.
 --SKIPIF--
 <?php if( !extension_loaded( 'intl' ) ) print 'skip'; ?>
 <?php if (version_compare(INTL_ICU_VERSION, '52.1') < 0) die('skip for ICU >= 52.1'); ?>