Mark up a GCC 3.4.3 failure of PTree.

[SVN r56318]

status/explicit-failures-markup.xml

@@ -3968,6 +3968,14 @@ for more information.
                 (Intel 11).
             </note>
         </mark-expected-failures>
+        <mark-expected-failures>
+            <test name="test_xml_parser_rapidxml"/>
+            <toolset name="gcc-3.4.3"/>
+            <note author="Sebastian Redl">
+                This ancient GCC doesn't like local const ints as template
+                parameters. Or something like that.
+            </note>
+        </mark-expected-failures>
     </library>
 
      <!-- pointer container -->