[basic.pre] Clarify that *declaration*s are not declarations (cplusplus#8187)

* [basic.pre] Clarify that *declaration*s are not declarations

The grammar production _declaration_ is distinct from the term "declaration" defined in [basic.pre].

Author: AlisdairM

source/basic.tex

@@ -97,6 +97,9 @@
 implicit declaration of an injected-class-name\iref{class.pre}.
 \end{itemize}
 \begin{note}
+The term declaration is not a synonym for the grammar non-terminal \grammarterm{declaration}\iref{dcl.pre}.
+\end{note}
+\begin{note}
 The interpretation of a \grammarterm{for-range-declaration} produces
 one or more of the above\iref{stmt.ranged}.
 \end{note}