RFR: JDK-8157336: Generation of classlists at build time should be configurable

[Tim Bell]

Erik:

> Generating a classlist at build time is not supported on all JVM 
> configurations. This patch adds a configure flag to control this build 
> step: --disable-generate-classlist. The default is to be enabled if 
> either a client or server JVM Variant is being built.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8157336
> Webrev: 
> http://cr.openjdk.java.net/~erikj/8157336/webrev.top.01/index.html

Looks good to me.

/Tim