Adjust class building types

Author: eernstg

specification/dartLangSpec.tex

@@ -24618,7 +24618,7 @@ \subsection{Class Building Types}
 \item $T$ is a type variable (\ref{generics}).
 \item $T$ is a function type (\ref{functionTypes}).
 \item $T$ is a type alias whose transitive alias expansion
-  (\ref{typedef}) does not denote a class.
+  (\ref{typedef}) does not denote a class building type.
 \item $T$ is an enumerated type (\ref{enums}).
 \item $T$ is a deferred type (\ref{staticTypes}).
 \end{itemize}