8007763: Refactoring: split up compute_generation_free_space() into two functions for class PSAdaptiveSizePolicy Summary: split up compute_generation_free_space() into two functions: compute_eden_space_size() + compute_old_gen_free_space(), each of which (if needed) can be reused without executing an overhead of the other. Reviewed-by: jmasa, tschatzl Contributed-by: tamao <tao.mao@oracle.com>

6843347: Boundary values in some public GC options cause crashes Summary: Setting some public integer options to specific values causes crashes or undefined GC behavior. This patchset adds the necessary argument checking for these options. Reviewed-by: jmasa, brutisso