Markup hardware_concurrency failure as expected on tru64 platforms, as support is not implemented

[SVN r42229]

status/explicit-failures-markup.xml

@@ -4663,6 +4663,14 @@ The Borland compiler fails to bind rvalues to the thread move constructor,
 choosing instead to bind them to the private (and unimplemented) copy constructor.
             </note>
         </mark-expected-failures>
+        <mark-expected-failures>
+            <test name="test_hardware_concurrency"/>
+            <test name="test_hardware_concurrency_lib"/>
+            <toolset name="*tru64"/>
+            <note author="Anthony Williams" date="2007-12-21">
+boost::thread::hardware_concurrency is not implemented and always returns 0 on this platform.
+            </note>
+        </mark-expected-failures>
     </library>
 
     <!-- tuple -->