JITWatch update

[Chris Newland]

JITWatch is now compatible with JDK9: https://twitter.com/chriswhocodes/status/898458577102352384

This brings the functionality back to the JDK8 level by fixing the assembly parser and supporting loading source jars with module paths.

With JDK9 you'll need to mount the classpath in the config rather than rely on TraceClassLoading statements.

Also fixed the performance regression in the JarScan tool caused by moving from the internal API class com.sun.tools.javap.JavapTask  to a ProcessBuilder wrapped around java/bin/javap. The overhead of wrapping meant JarScan took hours instead of minutes to parse large jars with 1000s of methods.

Using reflection to check if JavapTask is available restored the performance https://github.com/AdoptOpenJDK/jitwatch/issues/254

Am going to clean up a few bug reports and then look at better OSR compilation highlighting.

Cheers,

Chris