RFR: JDK9 b167: demos exist in JDK bundles

[Erik Joelsson]

We recently stopped building the JDK demos, or at least most of them. 
For client testing purposes we are still building some of them, and 
those are now ending up in the JDK bundle. Since we are very late in JDK 
9, we do not want to interrupt the testing procedures by moving these 
demos out of the jdk image. This patch restores the filtering of the jdk 
bundle to again exclude the demo directory.

Since these demo files are now only kept for use in testing, their 
proper place is actually in the test-image/bundle. This patch also adds 
them there to support the transition of the testing procedures.

Bug: https://bugs.openjdk.java.net/browse/JDK-8179867

Webrev: http://cr.openjdk.java.net/~erikj/8179867/webrev.01

/Erik