* kill.cc (main): Chack pid against INT_MIN and (U)INT_MAX since pid_t
	is 4 byte on all platforms.
	* mkgroup.c (main): Check domlist[i].id_offset against UINT_MAX since
	DWORD is 4 byte on all platforms.
	* mkpasswd.c (main): Ditto.
	* gendef: Use pause instead of calling yield throughout in x86_64 code.