git: openjdk/zgc: 2 new changesets

[Erik Österlund]

Changeset: b9ffcc40
Author:    Erik Österlund <eosterlund at openjdk.org>
Date:      2020-08-28 16:12:36 +0000
URL:       https://git.openjdk.java.net/zgc/commit/b9ffcc40

ZGC: Revert start_iteration placement

! src/hotspot/share/runtime/safepointMechanism.cpp

Changeset: 49acf9f7
Author:    Erik Österlund <eosterlund at openjdk.org>
Date:      2020-08-28 17:46:26 +0000
URL:       https://git.openjdk.java.net/zgc/commit/49acf9f7

ZGC: Update JFR stack trace lock rank

! src/hotspot/share/runtime/mutexLocker.cpp