RFR 8u backport: 8179084: HotSpot VM fails to start when AggressiveHeap is set

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8179084
JDK 9 changeset: 
http://hg.openjdk.java.net/jdk9/dev/hotspot/rev/f1cca489e9c6

webrev: http://cr.openjdk.java.net/~dholmes/8179084/webrev/

The functional fix in arguments.cpp is the same as in 9, just different 
line numbers.

The test had to be adjusted for the 8u test environment and other 
differences between 8 and 9:
- no @modules needed
- @requires vm.gc.parallel not supported
- test library location and package names are different
- PrintFlagsFinal output is different so needed to change pattern to match

The @requires was there because the test will only work on a VM which 
has a default GC that supports parallel GC. The only binaries we have in 
8u that would fail this is a JRE/JDK that defaults to the MinimalVM. But 
the MinimalVM only supports Compact1 and Compact2, and the test uses 
APIs from Compact3 anyway - so I added the test to the needs_compact3 
group in TEST.groups to deal with this limitation.

Testing: manual
          JPRT (I added the test to hotspot_gc for testing purposes)

Thanks,
David