RFR: JDK-8211130: Change to Oracle Developer Studio 12.6 for building on Solaris at Oracle

[Tim Bell]

Erik:

> It's time for Oracle to change the official compiler used for building
> OpenJDK on Solaris. The new version will be Oracle Developer Studio 12.6
> and the build will happen on Solaris 11.3. This patch changes the jib
> dependency to use the new devkit and updates the devkit generator script
> with the latest changes needed to produce the kit we are switching to.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8211130
>
> Webrev: http://cr.openjdk.java.net/~erikj/8211130/webrev.01/

Looks good.

/Tim