PERLVAR(Iunicode, U32) /* Unicode features: $ENV{PERL_UNICODE} or -C */
+PERLVAR(Isignals, U32) /* Using which pre-5.8 signals */
+
/* New variables must be added to the very end, before this comment,
* for binary compatibility (the offsets of the old members must not change).
* XSUB.h provides wrapper functions via perlapi.h that make this