Review request for JDK-8191878: Reduce code duplication in BeanLinker

[Attila Szegedi]

Hey folks,

I’m able to spend some free time again on OpenJDK development, and one thing I have on my plate is adding a REMOVE operation to Dynalink.

This CR however, is not yet it: that will require a CCC sponsorship etc. as I’ll be adding a new enum value to StandardOperations, and I will follow up separately once I’m done with it. 

What this is a refactoring of BeanLinker code to eliminate most of the code duplication between getElementGetter and getElementSetter methods. This would be justified on its own, but once I need to add the getElementRemover method, it will really pay off as then we won’t have triplication of similar code.

With that in mind, please review JDK-8191878 "Reduce code duplication in BeanLinker" at <http://cr.openjdk.java.net/~attila/8191878/webrev.jdk10> for <https://bugs.openjdk.java.net/browse/JDK-8191878>

Thanks,
  Attila.