Where is libiberty.h? (trying to compile MOL on Debian)

[Renaud Dreyer <rdreyer@math.berkeley.edu>]

I've been trying to compile mol-0.9.41 on my PowerMac 7300 running 
Debian Potato but it complains that libiberty.h is missing. In which 
package can I find this? A search of debian.org or of Usenet yielded 
no clue. Thanks,

           Renaud