Rename `iv_count` on shapes to `next_iv_index`

`iv_count` is a misleading name because when IVs are unset, the new
shape doesn't decrement this value. `next_iv_count` is an accurate, and
more descriptive name.

1 files changed, 1 insertions, 1 deletions

diff --git a/gc.c b/gc.c
index cc7b338062..b8c4bfb009 100644
--- a/gc.c
+++ b/gc.c
@@ -3434,7 +3434,7 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
                 VALUE klass = RBASIC_CLASS(obj);
 
                 // Increment max_iv_count if applicable, used to determine size pool allocation
-                uint32_t num_of_ivs = shape->iv_count;
+                uint32_t num_of_ivs = shape->next_iv_index;
                 if (RCLASS_EXT(klass)->max_iv_count < num_of_ivs) {
                     RCLASS_EXT(klass)->max_iv_count = num_of_ivs;
                 }