[jdk17u] RFR: 8270886: Crash in PhaseIdealLoop::verify_strip_mined_scheduling

[Tobias Hartmann]

Backport of [JDK-8270886](https://bugs.openjdk.java.net/browse/JDK-8270886). Applies cleanly. Approval is pending.

Thanks,
Tobias

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Commit messages:
 - 8270886: Crash in PhaseIdealLoop::verify_strip_mined_scheduling

Changes: https://git.openjdk.java.net/jdk17u/pull/101/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=101&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8270886
  Stats: 175 lines in 2 files changed: 171 ins; 4 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/101.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/101/head:pull/101

PR: https://git.openjdk.java.net/jdk17u/pull/101