ACATS tests are part of GCC and run as part of its testsuite, but the copy in GCC is a bit old. It might be a nice idea to package https://github.com/simonjwright/ACATS (and perhaps https://github.com/simonjwright/ACATS-grading too) to allow running a newer version of the tests. We'd ideally have the ebuild run them in src_test but also install them for manual use.
