RFR: JDK-8202920: jvm.cfg generation incorrect

[Erik Joelsson]

I took a further look at the jvm.cfg generation and reworked it 
completely. This change removes all the predefined jvm.cfg files and 
replaces them with a simple generation script. This should produce the 
same files as before JDK-8202683 for any configuration Oracle builds 
officially and zero. For special jvm variant combinations, it will stay 
closer to the official ones. See bug comments for details.

Bug: https://bugs.openjdk.java.net/browse/JDK-8202920

Webrev: http://cr.openjdk.java.net/~erikj/8202920/webrev.01/

/Erik