hg: jdk8u/jdk8u-dev/hotspot: 8240576: JVM crashes after transformation in C2 IdealLoopTree::merge_many_backedges

[denghui.ddh at alibaba-inc.com]

Changeset: 4373df7c4a92
Author:    fyang
Date:      2020-03-23 19:52 +0800
URL:       https://hg.openjdk.java.net/jdk8u/jdk8u-dev/hotspot/rev/4373df7c4a92

8240576: JVM crashes after transformation in C2 IdealLoopTree::merge_many_backedges
Reviewed-by: kvn
Contributed-by: hedongbo at huawei.com

! src/share/vm/opto/loopnode.cpp
+ test/compiler/loopopts/TestBeautifyLoops.java