I don't there's any test that could be done using the existing
instructions. The aliasing change is needed for the REV64 alias of the
REV instruction
(https://sourceware.org/ml/binutils/2015-11/msg00222.html) patch. That
includes tests that check that the instruction REV is preferred over its
aliases so are also  a test of this patch (which should probably have
been sent as part of the BFM, REV patch set).