RFR: JDK-8204922: Create bootcycle jib profiles

[Tim Bell]

Erik:

> In order to test bootcycle builds more easily at Oracle, we need
> specific jib profiles for them. This patch adds that. I also make the
> linux-aarch64 profile explicitly build the aarch64 port instead of the
> arm64 port as well as disable warnings-as-errors since we currently have
> the readdir warning in that configuration.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8204922
>
> Webrev: http://cr.openjdk.java.net/~erikj/8204093/webrev.01/

Looks good.

/Tim