mark xpressive unusable with sun compiler

[SVN r39596]

status/explicit-failures-markup.xml

@@ -5124,7 +5124,9 @@ for more information.
         </mark-unusable>
         <mark-unusable>
             <toolset name="sunpro-5_3-sunos"/>
+            <toolset name="sun-5.7"/>
             <toolset name="sun-5.8"/>
+            <toolset name="sun-5.9"/>
             <note refid="17"/>
         </mark-unusable>
     </library>