These bootloader files are required to boot on various architectures. They are provided here because you cannot install the bootloader rpms for an architecture you are not on. These files were taken from the following rpms, if you want the source then get the appropriate srpm:

elilo-3.6-4.ia64.rpm:
elilo-ia64.efi (named elilo.efi there)

yaboot-1.3.14-41.el6.ppc.rpm:
yaboot

Currently installed version of syslinux:
menu.c32
pxelinux.0
