HHVM encodes __pclass last, so disable these tests here.

The Hippo replacements are:
- tests/bson-deserialize-pclass-and-hex-001.phpt
- tests/bson-deserialize-pclass-and-hex-002.phpt

Author: derickr

tests/bson/bson-encode-003.phpt

@@ -1,6 +1,7 @@
 --TEST--
 BSON encoding: Encoding objects into BSON representation
 --SKIPIF--
+<?php if (defined("HHVM_VERSION_ID")) exit("skip HHVM encodes __pclass last"); ?>
 <?php require __DIR__ . "/../utils/basic-skipif.inc"?>
 --FILE--
 <?php

tests/bson/bson-toPHP-002.phpt

@@ -1,6 +1,7 @@
 --TEST--
 BSON\fromPHP(): Null type map values imply default behavior
 --SKIPIF--
+<?php if (defined("HHVM_VERSION_ID")) exit("skip HHVM encodes __pclass last"); ?>
 <?php require __DIR__ . "/../utils/basic-skipif.inc"?>
 --FILE--
 <?php