Add `const` to `irep` pointer in `os_memsize_of_irep`;
@@ -183,7 +183,7 @@ os_memsize_of_ivars(mrb_state* mrb, mrb_value obj)
}
static mrb_int
-os_memsize_of_irep(mrb_state* state, struct mrb_irep *irep)
+os_memsize_of_irep(mrb_state* state, const struct mrb_irep *irep)
{
mrb_int size, i;
size = (irep->slen * sizeof(mrb_sym)) +
