Don't know if this helps, but that is the x86 real-mode library:
"A library to provide support for making real-mode calls x86 calls. On x86 hardware, vm86 mode is used. On other platforms, x86 emulation is provided."
On Debian the package is know as libx86-1.
If it's not available in your distribution's repositories, I guess you'll have to compile it from source:
http://www.codon.org.uk/~mjg59/libx86/
Peter.