RFR: JDK-8232572: Add hooks for custom output dir in Bundles.gmk

[Tim Bell]

Erik:

> Our custom distribution packaging logic needs to be able to override the 
> output directory of bundles. This patch adds an OUTPUT_DIR parameter to 
> the SetupBundles macro. It also adds logging of the bundles being 
> created. The added % in the filter makes it possible to extend specific 
> product bundles under make targets that start with "product-bundles".
> 
> Webrev: http://cr.openjdk.java.net/~erikj/8232572/webrev.jdk14.01/
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8232572

Looks good.

Tim