Support overloading of the subscript operator[], including support for
built-in operator candidates. Test overloading of '&' and ','.

In C++, a comma expression is an lvalue if its right-hand
subexpression is an lvalue. Update Expr::isLvalue accordingly.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59643 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/www/cxx_status.html b/www/cxx_status.html
index 7c51fb3..6db2840 100644
--- a/www/cxx_status.html
+++ b/www/cxx_status.html
@@ -981,7 +981,7 @@
   <td>&nbsp;&nbsp;&nbsp;&nbsp;13.5.5 [over.sub]</td>

   <td class="na" align="center">N/A</td>  

   <td class="advanced" align="center"></td>

-  <td class="basic" align="center"></td>

+  <td class="advanced" align="center"></td>

   <td class="broken" align="center"></td>  

   <td></td>

 </tr>