[meta.reflection.result] move declaration of TCls earlier

Fixes NB US 117-178 (C++26 CD).

Author: jwakely

source/meta.tex

@@ -6123,10 +6123,15 @@
   otherwise, the value of \tcode{expr}.
 \end{itemize}
 
+\pnum
+Let \tcode{TCls} be the invented template:
+\begin{codeblock}
+template<T P> struct TCls;
+\end{codeblock}
+
 \pnum
 \returns
-\tcode{template_arguments_of(\reflexpr{TCls<$V$>})[0]},
-with \tcode{TCls} as defined below.
+\tcode{template_arguments_of(\reflexpr{TCls<$V$>})[0]}.
 \begin{note}
 This is a reflection of an object for class types,
 and a reflection of a value otherwise.
@@ -6135,11 +6140,7 @@
 \pnum
 \throws
 \tcode{meta::exception} unless
-the \grammarterm{template-id} \tcode{TCls<$V$>} would be valid
-given the invented template
-\begin{codeblock}
-template<T P> struct TCls;
-\end{codeblock}
+the \grammarterm{template-id} \tcode{TCls<$V$>} would be valid.
 
 \pnum
 \begin{example}