Actual problem is immediately below code. `e1->type` may be `Tenum`, so you can simply insert `->toBasetype()` befor calling `->nextOf()`

```cpp
    if ((e1->op == TOKstring || e1->op == TOKarrayliteral) &&
        (type->ty == Tpointer || type->ty == Tarray) &&
-        e1->type->nextOf()->size() == type->nextOf()->size()
+        e1->type->toBasetype()->nextOf()->size() == type->nextOf()->size()
       )
```