JDK 10 RFR 8181417: Code cleanups in com.sun.jdi

[Langer, Christoph]

Hi,

during integration work of the jdi library for one of our projects I spotted some places where a few cleanups could be done. I'd like to contribute this. It is mostly about import statements and formatting/empty lines. I think at this stage of JDK10 it's a good time for such kind of work.

Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8181417.0/
Bug: https://bugs.openjdk.java.net/browse/JDK-8181417

Thanks and best regards
Christoph