RFR: 8287809: Revisit implementation of memory session

[Maurizio Cimadamore]

This is a JDK 19 clone of: https://github.com/openjdk/jdk/pull/9017

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Commit messages:
 - Add missing files
 - Initial push

Changes: https://git.openjdk.org/jdk19/pull/22/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=22&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8287809
  Stats: 1751 lines in 39 files changed: 407 ins; 525 del; 819 mod
  Patch: https://git.openjdk.org/jdk19/pull/22.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/22/head:pull/22

PR: https://git.openjdk.org/jdk19/pull/22