Add papers adopted by the C++ committee in the June 2021 plenary

clang/www/cxx_status.html

@@ -1283,6 +1283,41 @@ <h2 id="cxx23">C++2b implementation status</h2>
       <td><a href="https://wg21.link/p2266r1">P2266R1</a></td>
       <td class="unreleased" align="center">Clang 13</td>
     </tr>
+    <tr>
+      <td><tt>if consteval</tt></td>
+      <td><a href="https://wg21.link/P1938R3">P1938R3</a></td>
+      <td class="none" align="center">No</td>
+    </tr>
+    <tr>
+      <td>Allow duplicate attributes</td>
+      <td><a href="https://wg21.link/P2156R1">P2156R1</a></td>
+      <td class="unreleased" align="center">Clang 13</td>
+    </tr>
+    <tr>
+      <td>Narrowing contextual conversions to bool</td>
+      <td><a href="https://wg21.link/P1401R5">P1401R5</a></td>
+      <td class="none" align="center">No</td>
+    </tr>
+    <tr>
+      <td>Trimming whitespaces before line splicing</td>
+      <td><a href="https://wg21.link/P2223R2">P2223R2</a></td>
+      <td class="full" align="center">Yes</td>
+    </tr>
+    <tr>
+      <td>Make declaration order layout mandated</td>
+      <td><a href="https://wg21.link/p1847r4">P1874R4</a></td>
+      <td class="full" align="center">Yes</td>
+    </tr>
+    <tr>
+      <td>C++ identifier syntax using UAX 31</td>
+      <td><a href="https://wg21.link/P1949R7">P1949R7</a></td>
+      <td class="none" align="center">No</td>
+    </tr>
+    <tr>
+      <td>Mixed string literal concatenation</td>
+      <td><a href="https://wg21.link/p2201r1">P2201R1</a></td>
+      <td class="full" align="center">Yes</td>
+    </tr>
 </table>
 </details>