RFR: 8081317: [NEWTEST] documented GC ratio tuning and new size options should be covered by regression tests

[Michail Chernov]

Hi,

Please review these changes for JDK-8081317. There are new tests to 
cover GC ratio tuning and new size options.

Webrev:  http://cr.openjdk.java.net/~mchernov/8081317/
Bug: https://bugs.openjdk.java.net/browse/JDK-8081317

TestMaxMinHeapFreeRatioFlags.java - Verify that heap size changes 
according to max and min heap free ratios.

TestMinAndInitialSurvivorRatioFlags.java - Test verifies that VM can 
start with any GC when MinSurvivorRatio and InitialSurvivorRatio flags 
passed and for Parallel GC it verifies that after start up survivor 
ratio is equal to InitialSurvivorRatio value and that actual survivor 
ratio will never be less than MinSurvivorRatio.

TestNewRatioFlag.java - Verify that heap divided among generations 
according to NewRatio.

TestNewSizeFlags.java - Verify that young gen size conforms values 
specified by NewSize, MaxNewSize and Xmn options.

TestSurvivorRatioFlag - Verify that actual survivor ratio is equal to 
specified SurvivorRatio value.

TestTargetSurvivorRatioFlag.java - Test if objects size is less than 
(survivor_size * TargetSurvivorRatio / 100) then objects are stayed in 
survivor space until MaxTenuringThreshold minor GC cycles. If more than 
(survivor_size * TargetSurvivorRatio / 100) objects were allocated, then 
test verifies that after MaxTenuringThreshold minor GC cycles survivor 
space is almost empty.

New changes were tested on different platforms including embedded jdk on 
Linux x86.

Thanks,
Michail