[jdk18u] RFR: 8283441: C2: segmentation fault in ciMethodBlocks::make_block_at(int)

[Tobias Hartmann]

Backport of [JDK-8283441](https://bugs.openjdk.java.net/browse/JDK-8283441). Applies cleanly. Approval is pending.

Thanks,
Tobias

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Commit messages:
 - 8283441: C2: segmentation fault in ciMethodBlocks::make_block_at(int)

Changes: https://git.openjdk.org/jdk18u/pull/155/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk18u&pr=155&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8283441
  Stats: 106 lines in 5 files changed: 94 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jdk18u/pull/155.diff
  Fetch: git fetch https://git.openjdk.org/jdk18u pull/155/head:pull/155

PR: https://git.openjdk.org/jdk18u/pull/155