RFR: JDK-8155632: Remove debuginfo from jmod files

[Tim Bell]

Hi Erik:

> The jmod files currently contain debug information and it has been 
> concluded that they shouldn't. This patch filters out the debug 
> information from the jmod files and adds a new build step in images to 
> copy the appropriate set of debuginfo into the images. Note that this 
> patch does not aim on changing the way we handle debuginfo in any 
> other way. This will be attacked more in depth in JDK-8150009, which 
> in turn depends on JDK-8136777.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8155632
> Webrev: http://cr.openjdk.java.net/~erikj/8155632/webrev.top.01/

Looks good to me.

Tim