Test questions

[hrstoyanov]

@AdamBien thanks for doing this test! A couple of suggestions:

• Please test with Java 13 and 14, especially with the ZGC and Shenandoah garbage collectors, both of which return unused memory (JEP-351)

• Java 13 also has JEP 350, which pre-compile classes (AOT), thus reducing the memory consumption of HotSpot JIT further

Overall, classic Java 9+ steadily improved memory usage to the point that GraalVM native image does not look that impressive anymore for memory savings.