[wwwdocs] Another C++20 table update

[Marek Polacek]

I've opened a bunch of PRs to track the status of C++2a features in G++.  This
patch updates the C++2a table accordingly.

While at it, I made a small clarification regarding P1152R4: only certain uses
of volatile are being deprecated, not volatile itself.

Index: cxx-status.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/projects/cxx-status.html,v
retrieving revision 1.92
diff -u -r1.92 cxx-status.html
--- cxx-status.html     5 Aug 2019 15:13:48 -0000       1.92
+++ cxx-status.html     5 Aug 2019 16:53:26 -0000
@@ -320,7 +320,7 @@
     </tr>
     <tr>
       <td><a href="http://wg21.link/p0784r7";>P0784R7</a></td>
-      <td class="unsupported center">No</td>
+      <td class="unsupported center">No (<a 
href="https://gcc.gnu.org/PR91369";>PR91369</a>)</td>
       <td> </td>
     </tr>
     <tr>
@@ -354,14 +354,14 @@
     <tr>
       <td> Parenthesized initialization of aggregates </td>
       <td><a href="http://wg21.link/p0960r3";>P0960R3</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91363";>PR91363</a>)</td>
       <td> __cpp_aggregate_paren_init &gt;= 201902</td>
     </tr>
     <tr>
       <td> Stronger Unicode requirements </td>
       <td><a href="http://wg21.link/p1041r4";>P1041R4</a><br/>
       <a href="http://wg21.link/p1139r2";>P1139R2</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91370";>PR91370</a>)</td>
       <td> </td>
     </tr>
     <tr>
@@ -380,45 +380,45 @@
       <td></td>
     </tr>
     <tr>
-      <td>Deprecating <code>volatile</code></td>
+      <td>Deprecating some uses of <code>volatile</code></td>
       <td><a href="http://wg21.link/p1152r4";>P1152R4</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91361";>PR91361</a>)</td>
       <td></td>
     </tr>
     <tr>
       <td><code>[[nodiscard("with reason")]]</code></td>
       <td><a href="http://wg21.link/p1301r4";>P1301R4</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91368";>PR91368</a>)</td>
       <td></td>
     </tr>
     <tr>
       <td><code>using enum</code></td>
       <td><a href="http://wg21.link/p1099r5";>P1099R5</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91367";>PR91367</a>)</td>
       <td></td>
     </tr>
     <tr>
       <td>Class template argument deduction for aggregates</td>
       <td><a href="http://wg21.link/p1816r0";>P1816R0</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91366";>PR91366</a>)</td>
       <td></td>
     </tr>
     <tr>
       <td>Class template argument deduction for alias templates</td>
       <td><a href="http://wg21.link/p1814r0";>P1814R0</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91365";>PR91365</a>)</td>
       <td></td>
     </tr>
     <tr>
       <td>Permit conversions to arrays of unknown bound</td>
       <td><a href="http://wg21.link/p0388r4";>P0388R4</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91364";>PR91364</a>)</td>
       <td></td>
     </tr>
     <tr>
       <td><code>constinit</code></td>
       <td><a href="http://wg21.link/p1143r2";>P1143R2</a></td>
-      <td class="unsupported">No</td>
+      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR91360";>PR91360</a>)</td>
       <td></td>
     </tr>
   </table>