[clang] [NFC][C++][Modules] Mark P2788R0(DR) as implemented and added more test (PR #144214)

[Yanzuo Liu via cfe-commits]

================
@@ -905,7 +905,7 @@ <h2 id="cxx20">C++20 implementation status</h2>
       </tr>
       <tr> <!-- from Issaquah 2023 -->
         <td><a href="https://wg21.link/P2788R0">P2788R0</a> (<a href="#dr">DR</a>)</td>
-        <td class="none" align="center">No</td>
+        <td class="none" align="center">Clang 17</td>
----------------
zwuis wrote:

```suggestion
        <td class="full" align="center">Clang 17</td>
```


https://github.com/llvm/llvm-project/pull/144214