RFR (L): JDK-8061308: Remove iCMS

[Bengt Rutisson]

Hi everyone,

Can I have a couple of reviews for this change?

HotSpot changes:
http://cr.openjdk.java.net/~brutisso/8061308/hotspot/

JDK changes:
http://cr.openjdk.java.net/~brutisso/8061308/jdk/
(Just a small update to a test library class.)

JBS bug:
https://bugs.openjdk.java.net/browse/JDK-8061308

The change removes the incremental mode of CMS. This work is part of JEP 
214 (http://openjdk.java.net/jeps/214). There are quite a few lines 
changed. Mostly it is just removal of code and it should hopefully be 
fairly straight forward to review.

One interesting side effect of removing iCMS was that the ConcEdenSpace 
(a subclass in the Space hierarchy) could be removed. It implemented the 
"soft-end" feature that only iCMS was taking advantage of. When I had 
removed ConcEdenSpace it turned out that its superclass, EdenSpace, was 
actually an unnecessary class that did not add anything so I removed 
that too. When I then went to update the comment in space.hpp that 
describes the Space hierarchy I noticed that the description of the 
hierarchy was completely out-dated. Rather than bringing it up-to-date I 
removed the comment. I think that type of information will only get 
out-dated quickly again and it is much easier to let your IDE create the 
correct type hierarchy view dynamically for you.

Thanks,
Bengt