Issue 2440: fix the handling of %n in Python/getargs.c's convertsimple(), extend Objects/abstract.c's PyNumber_Index() to accept PyObjects that have nb_int slots, and update test_getargs2 to test that an exception is thrown when __int__() returns a non-int object.

#include "Python.h"

#ifndef PLATFORM
#define PLATFORM "unknown"
#endif

const char *
Py_GetPlatform(void)
{
	return PLATFORM;
}