(Merge 3.3) sysmodule.c: fix sys_update_path(), use Py_ARRAY_LENGTH() to get the size of the fullpath buffer, not PATH_MAX. fullpath is declared using MAXPATHLEN or MAX_PATH depending on the OS, and PATH_MAX is not declared on IRIX.

#include "Python.h"

#ifndef PLATFORM
#define PLATFORM "unknown"
#endif

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