ublas: expect cw-8.3 failure

[SVN r25232]

status/explicit-failures-markup.xml

@@ -801,6 +801,7 @@ for more information.
         <mark-unusable>
             <toolset name="borland"/>
             <toolset name="borland-5.6.4"/>
+            <toolset name="cw-8.3"/>
             <note author="M.Stevens" refid="2"/>
         </mark-unusable>
         <test name="test2">