hg: jdk8u/jdk8u-dev/hotspot: 8219807: C2 crash in IfNode::up_one_dom(Node*, bool)

[shade at redhat.com]

Changeset: 5d306df084eb
Author:    thartmann
Date:      2019-04-30 14:49 +0200
URL:       http://hg.openjdk.java.net/jdk8u/jdk8u-dev/hotspot/rev/5d306df084eb

8219807: C2 crash in IfNode::up_one_dom(Node*, bool)
Summary: Guard against regions degraded to copies.
Reviewed-by: kvn

! src/share/vm/opto/ifnode.cpp
+ test/compiler/c2/TestIfWithDeadRegion.java