Fix type inferencing and syntax highlighting for private member references from nested closure

[eric-milles]

Consider the following:

void meth(org.w3c.dom.Element element, String rev, File dir) {
  dir.eachDir { dir2 ->
    dir2.eachDir { dir3 ->
      def artifacts = element.getElementsByTagName('artifact')
      process(artifacts, rev, dir3)
    }
  }
}
private void process(artifacts, String rev, File jardir) {}

The method call "process" is highlighted as unknown (underlined).

[eric-milles]