The cases were described in https://bugs.openjdk.java.net/browse/JDK-8162420

Need to modify existing test/add a new test to cover that cases.

Part of Sangheon description:
We resize the generations if sum of them is mismatching from initial heap size. (collectorPolicy.cpp:531)

line 531: if ((_initial_old_size + _initial_young_size) != _initial_heap_byte_size) {
...
line 535: size_t desired_young_size = _initial_heap_byte_size - _initial_old_size;
...
 } else {
line 551: _initial_young_size = desired_young_size;

Need to cover this code by tests.