Add a link.

llvm-svn: 18316
diff --git a/llvm/docs/CommandGuide/llvm-ar.pod b/llvm/docs/CommandGuide/llvm-ar.pod
index 99fdcb9..1c8d0ab 100644
--- a/llvm/docs/CommandGuide/llvm-ar.pod
+++ b/llvm/docs/CommandGuide/llvm-ar.pod
@@ -398,7 +398,7 @@
 
 =head1 SEE ALSO
 
-L<llvm-ranlib|llvm-ranlib>
+L<llvm-ranlib|llvm-ranlib>, L<ar(1)>
 
 =head1 AUTHORS