License to a file only available in Mozilla classic

We have been using the ifc.jar file that used to be available from
Netscape. We have some lawyers asking questions and have to figure out
under which license the file is distributed.

ifc11.jar can be found in
http://lxr.mozilla.org/classic/source/nav-java/stubs/classes/ifc11.jar

Is this file available under NPL or also under MPL/GPL/LGPL?

Just from general interest, what happened to ifc.jar, it seems to be
used by later versions of mozilla but I cannot find it and LXR seems to
not index JAR files.