Markup older Borland compilers that don't support enable_if

[SVN r40928]

status/explicit-failures-markup.xml

@@ -1273,6 +1273,14 @@
 
     <!-- filesystem -->
     <library name="filesystem">
+        <mark-unusable>
+          <toolset name="borland-5.6*"/>
+          <toolset name="borland-5.8*"/>
+          <note author="Beman Dawes">
+              This compiler does not support enable_if, which is needed by the
+              Boost.System library on which Boost.Filesystem depends.
+          </note>
+        </mark-unusable>
         <mark-unusable>
             <toolset name="intel-7.1-linux"/>
             <toolset name="intel-7.1-stdlib-default-linux"/>
@@ -4323,6 +4331,18 @@ for more information.
         </test>
     </library>
 
+    <!-- system -->
+    <library name="system">
+      <mark-unusable>
+        <toolset name="borland-5.6*"/>
+        <toolset name="borland-5.8*"/>
+        <note author="Beman Dawes">
+            This compiler does not support enable_if, which is required
+            by Boost.System.
+        </note>
+      </mark-unusable>
+    </library>
+
     <!-- test -->
     <library name="test">
         <mark-expected-failures>