[jdk8u-dev] RFR: 8255466: C2 crashes at ciObject::get_oop() const+0x0

[SendaoYan]

Hi all
This is backport of JDK-8255466, to fixes the corner case in C2.
Patch does not apply cleanly due to in jdk8u, the jtreg tag @run main need add `bootclasspath`.
New test fails without the patch, passes with it.

Additional testing:

- [ ] linux x64 tier1/2/3 jtreg test
- [ ] linux aarch64 tier1/2/3 jtreg test

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Commit messages:
 - Backport bb3f1238cb12c45ed85936d3b06eced0730d588f

Changes: https://git.openjdk.org/jdk8u-dev/pull/536/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=536&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8255466
  Stats: 74 lines in 2 files changed: 67 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/536.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/536/head:pull/536

PR: https://git.openjdk.org/jdk8u-dev/pull/536