[jdk11u-dev] RFR: 8296912: C2: CreateExNode::Identity fails with assert(i < _max) failed: oob: i=1, _max=1

[Goetz Lindenmaier]

I backport this for parity with 11.0.19-oracle.

I had to resolve the test @run description because -XX:+StresssIGVN is not in 11.

-------------

Commit messages:
 - Backport 502fa3eeea849cfcc50436602be1654695ef4e26

Changes: https://git.openjdk.org/jdk11u-dev/pull/1657/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1657&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296912
  Stats: 25 lines in 2 files changed: 20 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1657.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1657/head:pull/1657

PR: https://git.openjdk.org/jdk11u-dev/pull/1657