RFR: 8029186: regression-hotspot nightly failure: assert(FLAG_IS_DEFAULT(MaxNewSize) || MaxNewSize < MaxHeapSize) failed

[Stefan Johansson]

Hi,

Please review this fix for:
https://bugs.openjdk.java.net/browse/JDK-8029186

Webrev:
http://cr.openjdk.java.net/~sjohanss/8029186/webrev.00/

Summary:
There have been a lot of bugs due to corner cases with heap sizing 
flags. This change strives to fix this particular problem and at the 
same time somewhat simplify the collector policy. I've also added some 
assertions to ensure that the sizing of the heap is more correct.

Testing:
* JPRT sanity and JTREG
* Adhoc aurora run for tmtools tests
* Script that verifies that we don't get assertions during startup for 
different combinations of NewSize, MaxNewSize, OldSize, Xms and Xmx.

Thanks,
StefanJ