Add rb_hash_free for the GC to use

gc.c

@@ -3539,12 +3539,7 @@ obj_free(rb_objspace_t *objspace, VALUE obj)
         }
 #endif
 
-        if (RHASH_ST_TABLE_P(obj)) {
-            st_table *tab = RHASH_ST_TABLE(obj);
-
-            free(tab->bins);
-            free(tab->entries);
-        }
+        rb_hash_free(obj);
         break;
       case T_REGEXP:
         if (RANY(obj)->as.regexp.ptr) {

hash.c

@@ -1178,6 +1178,14 @@ hash_st_free_and_clear_table(VALUE hash)
     RHASH_ST_CLEAR(hash);
 }
 
+void
+rb_hash_free(VALUE hash)
+{
+    if (RHASH_ST_TABLE_P(hash)) {
+        hash_st_free(hash);
+    }
+}
+
 typedef int st_foreach_func(st_data_t, st_data_t, st_data_t);
 
 struct foreach_safe_arg {

internal/hash.h

@@ -87,6 +87,7 @@ int rb_hash_stlike_delete(VALUE hash, st_data_t *pkey, st_data_t *pval);
 int rb_hash_stlike_foreach_with_replace(VALUE hash, st_foreach_check_callback_func *func, st_update_callback_func *replace, st_data_t arg);
 int rb_hash_stlike_update(VALUE hash, st_data_t key, st_update_callback_func *func, st_data_t arg);
 VALUE rb_ident_hash_new_with_size(st_index_t size);
+void rb_hash_free(VALUE hash);
 
 static inline unsigned RHASH_AR_TABLE_SIZE_RAW(VALUE h);
 static inline VALUE RHASH_IFNONE(VALUE h);