Implement object shapes for T_CLASS and T_MODULE (#6637)

* Avoid RCLASS_IV_TBL in marshal.c
* Avoid RCLASS_IV_TBL for class names
* Avoid RCLASS_IV_TBL for autoload
* Avoid RCLASS_IV_TBL for class variables
* Avoid copying RCLASS_IV_TBL onto ICLASSes
* Use object shapes for Class and Module IVs

1 files changed, 1 insertions, 1 deletions

diff --git a/marshal.c b/marshal.c
index 59edbfe53a..d956260d96 100644
--- a/marshal.c
+++ b/marshal.c
@@ -523,7 +523,7 @@ hash_each(VALUE key, VALUE value, VALUE v)
 
 #define SINGLETON_DUMP_UNABLE_P(klass) \
     (rb_id_table_size(RCLASS_M_TBL(klass)) > 0 || \
-     (RCLASS_IV_TBL(klass) && RCLASS_IV_TBL(klass)->num_entries > 1))
+     rb_ivar_count(klass) > 1)
 
 static void
 w_extended(VALUE klass, struct dump_arg *arg, int check)