Tweak members_of note that not only special members may be implicitly-declared.

Author: jakubjelinek

source/meta.tex

@@ -5618,7 +5618,7 @@
 appear in the order in which they are declared.
 \begin{note}
 Base classes are not members.
-Implicitly-declared special members
+Implicitly-declared special members and comparison operator member functions
 appear after any user-declared members\iref{special}.
 \end{note}