RFR: 8258147: Modernize Nashorn code

[Attila Szegedi]

Hey folks, 

the openjdk bot for sending automated RFR emails based on PRs doesn’t work yet (Skara folks should be looking into it) so in the meantime I’ll just post PR links here for awareness:

I have a PR that’s essentially code modernization from Nashorn’s mostly Java 7(!!) compliant source code to Java 11 style + misc cleanups. If someone can give it a sanity check, it’d be appreciated.

<https://github.com/openjdk/nashorn/pull/5>

Thanks,
  Attila.