Marked variant as unusable on Tru64/CXX-6.5.

[SVN r30155]

status/explicit-failures-markup.xml

@@ -2874,6 +2874,7 @@ for more information.
         <mark-unusable>
             <toolset name="mipspro"/>
             <toolset name="sunpro-5_3-sunos"/>
+            <toolset name="tru64cxx65*"/>
             <note refid="2"/>
         </mark-unusable>
         <test name="recursive_variant_test">