true locatives, such that two locatives compare equal if and only if they
refer to the same place; but that doesn't work for these locatives.
-\begin{describe}{cls}{loc}
+\begin{describe}{cls}{locative}
The type of locative objects.
\end{describe}
-\begin{describe}{fun}{locp @<object> @> @<generalized-boolean>}
+\begin{describe}{fun}{locativep @<object> @> @<generalized-boolean>}
Return non-nil if and only if @<object> is a locative.
\end{describe}