Missing Java 9 support for Gradle projects

[uudashr]

A lot of errors shows on "problems" tab

Environment

• Operating System: Mac OS X Sierra
• JDK version: build 9+181
• Visual Studio Code version: 1.17.0
• Java extension version: 0.11.0

Steps To Reproduce

1. Clone from https://github.com/VaughnVernon/IDDD_Samples
2. Open project

[fbricon]

At the moment we have experimental Java 9 support for Maven based projects in our CI builds (try the latest *.vsix from http://download.jboss.org/jbosstools/jdt.ls/staging/).
However, Java 9 support for Gradle projects is not available yet. We depend on the upstream Buildship project to release Java 9 support for Gradle in Eclipse.

@oehme @donat, if there's a Buildship build we can use, please let me know.

[donat]

@fbricon It's not yet publicly documented, but we are planning to fix Buildship to work on Java 9 in the 2.2 release. You can follow the progress here: https://github.com/eclipse/buildship/milestone/9

[fbricon]

Duplicated by #359.

Fixed in master, by embedding the latest BuildShip 2.2 build.