RFR (S) 8252660: Shenandoah: support manageable SoftMaxHeapSize option

[Aleksey Shipilev]

On 9/2/20 2:16 AM, Zhengyu Gu wrote:
> Looks fine to me in general.
> 
> Tests' @requires are not consistent, some miss  '!vm.graal.enabled'

D'oh. That means the test I copy-pasted it from is also inconsistent. I fixed this oddity in new 
tests, and will do another sweep over existing tests in a separate issue.

Updated:
   https://cr.openjdk.java.net/~shade/8252660/webrev.02/

-- 
Thanks,
-Aleksey