How to instrument static initializers?

[trask]

Instrumenting static initializers is useful if we want to execute some code on class initialization (since we can't typically execute code during transformation itself since that can load more classes which will then not be instrumented since transform() isn't called on classes loaded inside of transform()).

Not sure why not able to instrument them via normal TypeInstrumentation.transformers() advice, suspect maybe because the underlying class doesn't have a static initializer to instrument. We may need to use LoadedTypeInitializer, but that wasn't working for me either, need to investigate further.

see #2672 (comment)