PowerMock tests aren't accounted for in JaCoCo coverage

Despite the version hold on JaCoCo, PowerMock tests don't appear in the coverage results; for example https://sonar.opendaylight.org/drilldown/measures/12541?metric=coverage&rids[]=15639&rids[]=45971 currently shows 0.1% coverage in NeutronL3Adapter, yet the test code covers over 60% of that class (as measured independently using IntelliJ and JaCoCo).

The latest version of PowerMock (1.6.4) is supposed to fix this, but apparently doesn't. https://git.opendaylight.org/gerrit/#/c/32427/ shows how to instrument the code so it gets measured correctly. That unfortunately causes a number of "class already instrumented" errors to be logged, so it feels sub-optimal.

I'm investigating whether the latest version of JaCoCo (which would involve a Sonar plugin upgrade) fixes things.