Added note about being able to XFAIL based on llvmgcc version.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27856 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/TestingGuide.html b/docs/TestingGuide.html
index ac8e72b..2b7938d 100644
--- a/docs/TestingGuide.html
+++ b/docs/TestingGuide.html
@@ -323,14 +323,14 @@
 that you might find useful when writing <tt>RUN</tt> lines.</p>
 
 <p>Lastly, you can easily mark a test that is expected to fail on a
-specific platform by using the <tt>XFAIL</tt> keyword. Xfail lines are
+specific platform or with a specific version of llvmgcc by using the <tt>XFAIL</tt> keyword. Xfail lines are
 specified in the comments of the test program using <tt>XFAIL</tt>,
 followed by a colon, and one or more regular expressions (separated by
 a comma) that will match against the target triplet for the
 machine. You can use * to match all targets. Here is an example of an
 <tt>XFAIL</tt> line:</p>
 <pre>
-; XFAIL: darwin,sun
+; XFAIL: darwin,sun,llvmgcc4
 </pre>
 
 </div>