Review request: Build infra update

[Erik Joelsson]

After achieving the milestone of equivalent images from the new and old 
build, this is a good time to refresh build-infra in jdk8. Here is a 
webrev with the proposed changes:

http://cr.openjdk.java.net/~erikj/build-infra5/webrev.01/ 
<http://cr.openjdk.java.net/%7Eerikj/build-infra5/webrev.01/>

Unfortunately the builds will not be as equal in jdk8 as in the 
build-infra forest due to bug "JDK-8000518 - Javac generates duplicate 
name_and_type constant pool entry for class BinaryOpValueExp.java". 
Running the comparison script also takes a very long time because of it.

/Erik