Heal HEID.
* eRROR_ID: use FSLIT() rather than SLIT() to have "error" be added to
the FastString hash table rather than as an ext. C string; the Binary
instance for FastString can't handle the latter, only the former.
[any deep reasons why not?]
\end{code}
\begin{code}
-eRROR_ID = pc_bottoming_Id errorIdKey pREL_ERR SLIT("error") errorTy
+eRROR_ID = pc_bottoming_Id errorIdKey pREL_ERR FSLIT("error") errorTy
errorTy :: Type
errorTy = mkSigmaTy [openAlphaTyVar] [] (mkFunTys [mkListTy charTy] openAlphaTy)