[wwwdocs] Document feature test macro for C++ constexpr dynamic alloc

[Jonathan Wakely via Gcc-patches]

OK for wwwdocs?


---
 htdocs/projects/cxx-status.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/htdocs/projects/cxx-status.html b/htdocs/projects/cxx-status.html
index 0ff9e94d..d2d6eab4 100644
--- a/htdocs/projects/cxx-status.html
+++ b/htdocs/projects/cxx-status.html
@@ -599,7 +599,7 @@
     <tr>
       <td><a href="https://wg21.link/p0784r7";>P0784R7</a></td>
       <td class="supported center"><a 
href="../gcc-10/changes.html#cxx">10</a></td>
-      <td> </td>
+      <td> __cpp_constexpr_dynamic_alloc &gt;= 201907 </td>
     </tr>
     <tr>
       <td> Feature test macros </td>
-- 
2.31.1