gv_check(): use aux flag rather than IsCOW

Currently the SVf_IsCOW flag doesn't have any meaning for HVs,
except that it is used in the specific case of gv_check() to temporarily
mark a stash as being scanned. Since stashes will have the HV_AUX fields,
we can use a flags bit in the new xhv_aux_flags field instead.

This then potentially frees up the SVf_IsCOW for use as a new general flag
bit for *all* HVs (including non-stash ones).

1 files changed, 2 insertions, 0 deletions

diff --git a/hv.h b/hv.h
index 498e6f01f6..5ad1459a2e 100644
--- a/hv.h
+++ b/hv.h
@@ -122,6 +122,8 @@ struct xpvhv_aux {
     U32         xhv_aux_flags;      /* assorted extra flags */
 };
 
+#define HvAUXf_SCAN_STASH   0x1   /* stash is being scanned by gv_check */
+
 /* hash structure: */
 /* This structure must match the beginning of struct xpvmg in sv.h. */
 struct xpvhv {