[sh/jdk8] Backport Shenandoah with large pages and small heap and test

[Aleksey Shipilev]

On 6/16/21 6:15 PM, Zhengyu Gu wrote:
> Webrev:
> http://cr.openjdk.java.net/~zgu/shenandoah/largepage_smallheap/webrev.00/

Indenting is a bit off here:

  523    // Make sure region size and heap size are page aligned.
  524   // If large pages are used, we ensure that region size is aligned to large page size if
  525   // heap size is large enough to accommodate minimal number of regions. Otherwise, we align
  526   // region size to regular page size.

Otherwise looks good!

-- 
Thanks,
-Aleksey