[jdk16] RFR: 8257621: JFR StringPool misses cached items across consecutive recordings

[Markus Grönlund]

Greetings,

this change fixes problems with the StringPool as it relates to chunk rotations.

Thanks
Markus

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Commit messages:
 - whitespace
 - rephrasing
 - javadoc update
 - Reintroduce string pool generation

Changes: https://git.openjdk.java.net/jdk16/pull/18/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=18&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8257621
  Stats: 183 lines in 13 files changed: 79 ins; 54 del; 50 mod
  Patch: https://git.openjdk.java.net/jdk16/pull/18.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/18/head:pull/18

PR: https://git.openjdk.java.net/jdk16/pull/18