Hover/Navigation for types not working in module-info.java

[fbricon]

In a Java 9 project with a module-info.java like

import java.sql.Driver;
import foo.bar.MyDriver;

module org.java9.test {
  requires java.sql;
  exports foo.bar;
  provides Driver with MyDriver;
}

Hovering over Driver doesn't display the java.sql.Driver javadoc. Works for MyDriver, a class from the workspace.
ctrl+click navigation doesn't work at all for Driver or MyDriver.

Everything works for when hovering or clicking on the import definitions

[fbricon]

This is caused by a bug in jdt, where compilationUnit.codeSelect returns several results. The import statements, giving context, are ignored instead of reducing the result list to 1 proper value. Hover and Navigation require 1 unambiguous result so they return nothing. The same bug exists in Eclipse IDE upstream: https://bugs.eclipse.org/bugs/show_bug.cgi?id=526326

[fbricon]

One way to mitigate that issue is to avoid using imports and use FQCN for all types referenced in module-info.java

[fbricon]

Had to revert changes bringing the Oxygen.2 bits as they cause #501