[PARSE BUG]: doesn't correctly parse member function pointers

### Problem description

From https://isocpp.org/wiki/faq/pointers-to-members

### C++ code that can't be parsed correctly (please double-check that https://robotpy.github.io/cxxheaderparser/ has the same error)

```text
typedef  int (Fred::*FredMemFn)(char x, float y);
```
