hg: jdk8u/monojdk8u-dev: 8253353: Crash in C2: guarantee(n != NULL) failed: No Node

[zgu at redhat.com]

Changeset: a6f3a08975f8
Author:    kvn
Date:      2021-01-28 16:16 +0000
URL:       https://hg.openjdk.java.net/jdk8u/monojdk8u-dev/rev/a6f3a08975f8

8253353: Crash in C2: guarantee(n != NULL) failed: No Node
Reviewed-by: vlivanov, neliasso
Contributed-by: Fei Yang <fyang at openjdk.org>

! hotspot/src/share/vm/opto/loopnode.cpp
! hotspot/src/share/vm/opto/loopnode.hpp
+ hotspot/test/compiler/loopopts/TestNestedIrreducibleLoops.jasm
+ hotspot/test/compiler/loopopts/TestNestedIrreducibleLoopsMain.java