RFR (M): JDK-8025166: Add regression tests on documented GC ratio tuning and new size options

[Filipp Zhinkin]

Hi,

please review following change, that adds regression tests on various 
heap ratio tuning options.

Bug: https://bugs.openjdk.java.net/browse/JDK-8025166
WebRev: http://cr.openjdk.java.net/~kshefov/8025166/webrev.00/
Testing done: JPRT, manual, automated on various platforms

Description of tests:

gc/arguments/TestMaxMinHeapFreeRatioFlags.java
Covered options: -Xminf -Xmaxf MaxHeapFreeRatio MinHeapFreeRatio.
Verify that overall heap size (for G1) or old gen size (for Serial and CMS)
is changing in order to conform Max/MinHeapFreeRatio.

gc/arguments/TestMinAndInitialSurvivorRatioFlags.java
Covered options: MinSurvivorRatio, InitialSurvivorRatio.
Verify that right after start up actual survivor ratio is close to 
InitialSurvivorRatio,
and that it will never be less than MinSurvivorRatio (for Parallel GC).

gc/arguments/TestNewRatioFlag.java
Covered options: NewRatio
Verify that actual new ratio is equal to passed NewRatio value.

gc/arguments/TestNewSizeFlags.java
Covered options: NewSize, MaxNewSize, -Xmn.
Verify that actual size of young space is lying between NewSize and 
MaxNewSize (for all GCs),
and that max size is equal to MaxNewSize (for non-G1 GCs).

gc/arguments/TestSurvivorRatioFlag.java
Covered options: SurvivorRatio.
Verify that actual survivor ratio is close to passed SurvivorRatio value.

gc/arguments/TestTargetSurvivorRatioFlag.java
Covered options: TargetSurvivorRatio.
Verify that TargetSurvivorRatio affects actual tenuring threshold (for 
Serial, CMS and G1).

Thanks,
Filipp.