RFR: JDK-8027371 Add JDI tests for breakpointing and stepping in lambda code

[Staffan Larsen]

We currently don't have any debugger tests that explicitly exercises lambdas. I have created two tests that at least provide some kind of red-face testing. They aren't very comprehensive, but I still think they add value.

webrev: http://cr.openjdk.java.net/~sla/8027371/webrev.00/
bug: https://bugs.openjdk.java.net/browse/JDK-8027371

Thanks,
/Staffan