[jdk18u] RFR: 8279412: [JVMCI] failed speculations list must outlive any nmethod that refers to it

[Tobias Hartmann]

Backport of [JDK-8279412](https://bugs.openjdk.java.net/browse/JDK-8279412). Applies cleanly. Fix request is pending.

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Commit messages:
 - 8279412: [JVMCI] failed speculations list must outlive any nmethod that refers to it

Changes: https://git.openjdk.java.net/jdk18u/pull/16/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk18u&pr=16&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8279412
  Stats: 41 lines in 2 files changed: 29 ins; 10 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk18u/pull/16.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk18u pull/16/head:pull/16

PR: https://git.openjdk.java.net/jdk18u/pull/16