Add support for Java 9+ modulepath entries in projects

[eric-milles]

Currently the JDK/JRE modules are bootstrapped using Eclipse's class loader. This requires the use of the same Java version for eclipse as you want for your project. For proper support on part with Java 8 and below classpath, a Java 9+ project will need its modulepath entries discoverable (through org.eclipse.jdt.launching.JavaRuntime.computeUnresolvedRuntimeDependencies(IJavaProject)?) and supported by some class loader. See GroovyClassLoaderFactory.