[jdk17u-dev] RFR: 8309862: Unsafe list operations in JfrStringPool

[Aleksey Shipilev]

Unclean backport to fix the important JFR bug and matches `17.0.9-oracle`. There are a number of contextual differences: `NULL` -> `nullptr` renames are not there,  Object Sampling is not there. I just reapplied the conflicting chunks to yield the similar diff.

Additional testing:
 - [x] macos-aarch64-server-fastdebug, `jdk/jfr`

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Commit messages:
 - Backport 05f896a153ee950b21bae251d2870a8adfe4f04a

Changes: https://git.openjdk.org/jdk17u-dev/pull/1439/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1439&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8309862
  Stats: 74 lines in 5 files changed: 44 ins; 13 del; 17 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1439.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1439/head:pull/1439

PR: https://git.openjdk.org/jdk17u-dev/pull/1439