markup test weighted_tail_variate_means for acc toolset: takes too long to compile

[SVN r47896]

status/explicit-failures-markup.xml

@@ -58,6 +58,7 @@
       </mark-expected-failures>
       <mark-expected-failures>
         <test name="weighted_tail_variate_means"/>
+        <toolset name="acc"/>
         <toolset name="hp_cxx-71*"/>
         <note author="Markus Schoepflin">
           This failure is caused by a timeout when compiling the test. It