Ada binaries for powerpc64le-linux-gnu can be found at [1], these should be good for bootstrapping (or install gnat-4.8 in Ubuntu 14.04 LTS). Ada should then be buildable from the 4.9.0 release. Install the deb, or use ar(1) on the deb file to extract the files. Thanks to Ulrich Weigand helping a lot with the initial bootstrap.
Matthias [1] https://launchpad.net/ubuntu/+source/gcc-snapshot/20140405-0ubuntu1
