[jdk17u-dev] RFR: 8290822: C2: assert in PhaseIdealLoop::do_unroll() is subject to undefined behavior

[Goetz Lindenmaier]

I backport this for parity with 17.0.8-oracle.

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Commit messages:
 - Backport cd77fcfb5f9156e5f0909fa15a842dde6c25c66a

Changes: https://git.openjdk.org/jdk17u-dev/pull/1300/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1300&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8290822
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1300.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1300/head:pull/1300

PR: https://git.openjdk.org/jdk17u-dev/pull/1300