revert is_undefined back to ref match, re:
@@ -1575,7 +1575,7 @@ impl CodeIndex {
pub fn is_undefined(&self) -> bool {
let index_ptr = &self.0.borrow().0;
- if let IndexPtr::Undefined = index_ptr {
+ if let &IndexPtr::Undefined = index_ptr {
true
} else {
false
