Please review incremental change for 8055186 / 8055529

[Attila Szegedi]

Please review <http://cr.openjdk.java.net/~attila/8055186/webrev.01> It's the incremental change for the backport that deals with the remarks we got from the maintainers. I also filed this as a separate issue <https://bugs.openjdk.java.net/browse/JDK-8055529> "Clean up the bin directory" that I'll apply to the 9 repo (I'll include it in the backport message too so JBS can track it in the backport).

Thanks,
  Attila.