The tag is present in Lintian version 2.104.264. That is the most recent version we know about.
The referenced file seems to be from a libtool version older than 1.5.2-2. This might lead to build errors on some newer architectures not known to this libtool.
Please ask your upstream maintainer to re-libtoolize the package or do it yourself if there is no active upstream. You will also need to run Autoconf to regenerate the configure script. Usually it is best to do this during the build by depending on autoconf, libtool, and automake if it is used, and then running:
autoreconf -i --force
before running configure. Depending on how old the package is, this may
require additional modifications to
configure.in or other work. If you do this during the build,
determine which files it will add or update and be sure to remove those
files in the clean target.
If you have fixed architecture-specific issues with minimal patches, rather than updating libtool, and verified that it builds correctly, please override this tag. Lintian will not be able to verify that.