PyEval_GetFuncName is bad API because

1. It hardcodes a limited number of function classes (which doesn't even include all function classes in the core interpreter) instead of supporting duck-typing.
2. In case of a "function" object, it relies on a borrowed reference to the function.
3. It is returning a C string instead of a Python string, so we cannot return a new reference even if we wanted to.

Since PyEval_GetFuncName and PyEval_GetFuncDesc are always used together, we might as well replace them by a single function with a proper API.