take care of USE_LAZY_LOAD=1.

On USE_LAZY_LOAD=1, the iseq should be loaded. So rb_iseq_check()
is needed. Furthermore, now lazy loading with builtin_function_table
is not supported, so it should cancel lazy loading.

builtin.c

@@ -51,7 +51,7 @@ rb_load_with_builtin_functions(const char *feature_name, const struct rb_builtin
     vm->builtin_function_table = NULL;
 
     // exec
-    rb_iseq_eval(iseq);
+    rb_iseq_eval(rb_iseq_check(iseq));
 }
 
 #endif

compile.c

@@ -11499,7 +11499,11 @@ ibf_load_iseq(const struct ibf_load *load, const rb_iseq_t *index_iseq)
 #if IBF_ISEQ_DEBUG
 	    fprintf(stderr, "ibf_load_iseq: loading iseq=%p\n", (void *)iseq);
 #endif
-	    rb_ibf_load_iseq_complete(iseq);
+            rb_ibf_load_iseq_complete(iseq);
+#else
+            if (GET_VM()->builtin_function_table) {
+                rb_ibf_load_iseq_complete(iseq);
+            }
 #endif /* !USE_LAZY_LOAD */
 
 #if IBF_ISEQ_DEBUG