After JDK-8224820, ZAddressSpace{Start,End,Size} is not used for
anything other than being printed, so they can be removed. Also, the two
last uses of ZAddressReserved* can easily be replaced.
Bug: https://bugs.openjdk.java.net/browse/JDK-8231270
Webrev: http://cr.openjdk.java.net/~pliden/8231270/webrev.0
/Per