The libffi is currently declared as toolexeclib_LTLIBRARIES. In many
cases, toolexeclib libraries will be installed in /usr/lib, so it
doesn't make any difference.
However, with multilib toolchains, they get installed in a
subdirectory of /usr/lib/. For example, with a Sourcery CodeBench
PowerPC toolchain, if the e500mc multilib variant is used, the libffi
library gets installed in /usr/lib/te500mc/. This is due to the
following code in the configure script:
case $multi_os_directory in
.) ;; # Avoid trailing /.
*) toolexeclibdir=$toolexeclibdir/$multi_os_directory ;;
Once the library is installed in /usr/lib/te500mc/, nothing works
because this installation location is inconsistent with the
installation location declared in libffi.pc.
So, instead of using this bizarre toolexeclib_LTLIBRARIES, simply use
the more standard lib_LTLIBRARIES, which ensures that the libffi
library is always installed in /usr/lib.