git: openjdk/jdk16u: 8265239: Shenandoah: Shenandoah heap region count could be off by 1

[Zhengyu Gu]

Changeset: 319621c3
Author:    Zhengyu Gu <zgu at openjdk.org>
Date:      2021-05-12 19:12:07 +0000
URL:       https://git.openjdk.java.net/jdk16u/commit/319621c31ccb639f3fcaaa63585c0feb4c0e3bb2

8265239: Shenandoah: Shenandoah heap region count could be off by 1

Backport-of: ff5bb8cf693c58a14063a351f535e3a55e51e8db

! src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
! src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp