[jdk21u-dev] RFR: 8335709: C2: assert(!loop->is_member(get_loop(useblock))) failed: must be outside loop

[Goetz Lindenmaier]

I backport this for parity with 21.0.6-oracle.

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Commit messages:
 - Backport 0ddf54e222104469669f611804ae55e2685f54fb

Changes: https://git.openjdk.org/jdk21u-dev/pull/1079/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1079&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8335709
  Stats: 61 lines in 2 files changed: 58 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1079.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1079/head:pull/1079

PR: https://git.openjdk.org/jdk21u-dev/pull/1079