Remove WG14 N3563

This paper had only non-normative changes and was already covered by
existing nullptr_t test coverage.

Author: AaronBallman

clang/www/c_status.html

@@ -361,11 +361,6 @@ <h2 id="c2y">C2y implementation status</h2>
       <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3532.pdf">N3532</a></td>
       <td class="full" align="center">Yes</td>
 	</tr>
-    <tr>
-      <td>Representation of Pointers and nullptr_t</td>
-      <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3563.pdf">N3563</a></td>
-      <td class="unknown" align="center">Unknown</td>
-	</tr>
     <tr>
       <td>Classification of the register storage-class specifier</td>
       <td><a href="https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3544.txt">N3544</a></td>