+ *
+ * It's useful if StgInt/StgWord are always the same as long, so that
+ * we can use a consistent printf format specifier without warnings on
+ * any platform. Fortunately this works at the moement; if it breaks
+ * in the future we'll have to start using macros for format
+ * specifiers (c.f. FMT_StgWord64 in Rts.h).