Bring SvOOK_on back, but simpler

Commit 404dce59 removed it, because nothing in core or CPAN was using
it and it is not part of the API.

Nothing in core was using it because it was unusable as previously
defined (with SvIOK_off).

This commit brings it back, but now it is a simple flag-setting macro,
that will actually be usable by the core.

1 files changed, 1 insertions, 0 deletions

diff --git a/sv.h b/sv.h
index dcd53f79d3..33a61be109 100644
--- a/sv.h
+++ b/sv.h
@@ -848,6 +848,7 @@ in gv.h: */
 				 ? mg_find(sv,PERL_MAGIC_vstring) : NULL)
 
 #define SvOOK(sv)		(SvFLAGS(sv) & SVf_OOK)
+#define SvOOK_on(sv)		(SvFLAGS(sv) |= SVf_OOK)
 #define SvOOK_off(sv)		((void)(SvOOK(sv) && sv_backoff(sv)))
 
 #define SvFAKE(sv)		(SvFLAGS(sv) & SVf_FAKE)