CWG3089 const-default-constructible improperly handles std::meta::info

Fixes NB US 39-076 (C++26 CD).

Author: eisenwave

source/declarations.tex

@@ -5092,32 +5092,38 @@
 \end{itemize}
 
 \pnum
-A class type \tcode{T} is \defn{const-default-constructible} if
+A type \cv{}~\tcode{T} is \defn{const-default-constructible} if
+\begin{itemize}
+\item
+\tcode{T} is \tcode{std::meta::info};
+\item
+\tcode{T} is \tcode{std::nullptr_t};
+\item
 default-initialization of \tcode{T} would invoke
-a user-provided constructor of \tcode{T} (not inherited from a base class)
-or if
+a user-provided constructor of \tcode{T} (not inherited from a base class);
+\item
+\tcode{T} is a class type where
 \begin{itemize}
 \item
-each direct non-variant non-static data member \tcode{M} of \tcode{T}
-has a default member initializer
-or, if \tcode{M} is of class type \tcode{X} (or array thereof),
-\tcode{X} is const-default-constructible,
+each direct non-variant non-static data member of \tcode{T}
+has a default member initializer or
+is of const-default-constructible type,
 \item
 if \tcode{T} is a union with at least one non-static data member,
 exactly one variant member has a default member initializer,
 \item
 if \tcode{T} is not a union,
-for each anonymous union member with at least one non-static data member (if any),
-exactly one non-static data member has a default member initializer, and
+the type of each anonymous union member is const-default-constructible, and
+\item
+each potentially constructed base class of \tcode{T} is const-default-constructible; or
+\end{itemize}
 \item
-each potentially constructed base class of \tcode{T} is const-default-constructible.
+\tcode{T} is an array of const-default-constructible type.
 \end{itemize}
 
 If a program calls for the default-initialization of an object of a
 const-qualified type \tcode{T},
-\tcode{T} shall be \tcode{std::meta::\linebreak info}
-or a const-default-constructible class type,
-or array thereof.
+\tcode{T} shall be a const-default-constructible type.
 
 \pnum
 To