[jdk8u-dev] RFR: 8202952: C2: Unexpected dead nodes after matching

[Dongbo He]

I would like to backport this patch to fix crash during C2 compilation. 

This patch doesn't apply cleanly due to context differences, and
I selected fuzzer tests from Fei Yang because the tests in the original commit cannot be reproduced on JDK8u.

Performed hotspot jtreg test on linux x86-64 platforms with -Xcomp options, new test fails without product change and passes with it.

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

Commit messages:
 - Backport 50e3aa4150dc1dd18870c5725666188ab38ab7d5

Changes: https://git.openjdk.org/jdk8u-dev/pull/291/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=291&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8202952
  Stats: 68 lines in 2 files changed: 68 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/291.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/291/head:pull/291

PR: https://git.openjdk.org/jdk8u-dev/pull/291