mark up expected accumulators failures

status/explicit-failures-markup.xml

@@ -77,6 +77,12 @@
         <toolset name="acc"/>
         <note author="Boris Gubenko" refid="47"/>
       </mark-expected-failures>
+      <mark-expected-failures>
+        <test name="p_square_cumul_dist"/>
+        <test name="weighted_p_square_cumul_dist"/>
+        <toolset name="*"/>
+        <note author="Eric Niebler" refid="53"/>
+      </mark-expected-failures>
     </library>
 
     <!-- minmax -->
@@ -7031,5 +7037,9 @@ This platform doesn't supports Boost.Chrono.
         This test requires lambda function support.
     </note>
 
+    <note id="53">
+        This test has not been updated to accomodate changes in Boost.Random.
+    </note>
+
 </explicit-failures-markup>