haul in all the unfoldings for B, in case the module that imports A *is*
compiled with -O. I think this is the case.]
+SimonM [30/11/2007]: I believe the above is all out of date; the
+current implementation doesn't do it this way. Instead, when any of
+the dependencies of a declaration changes, the version of the
+declaration itself changes.
\begin{code}
#include "HsVersions.h"