This is the analogue of 9f63b62e but for getattr instead of setattr:
previously there was no way to run the default getattr logic, since
getattrInternalGeneral would always check for a custom __getattr__
or __getattribute__.  This meant that object.__getattribute__ was
the same thing as getattr() and that PyObject_GenericGetAttr was the
same as PyObject_GetAttr, which were not correct.