#534 nm: add support for i386pep

[Roger]

Hello,

This is again used by the Xen build system in order to create the EFI image. The exact rune is:

$ nm -pa --format=sysv xen.efi
nm: xen.efi: File format not recognized

I'm also attaching the sample file in case someone wants to try to add support for i386pep.

Thanks, Roger.

[Ed Maste]

What does it want to do with the nm output?

I think this is unlikely to be supported in ELF Tool Chain; PE output in elfcopy is a reasonable "special case" as it already handles binary, .hex etc. output, but there's no abstraction layer like BFD to easily support non-ELF formats in other tools and it's outside of the real scope of the project.