[foreign-jextract] RFR: 8254682: Close MemorySegments passed to upcalls after the upcall is done [v2]

[Jorn Vernee]

> These are the jextract fixes needed after: https://github.com/openjdk/panama-foreign/pull/379

Jorn Vernee has refreshed the contents of this pull request, and previous commits have been removed. The incremental
views will show differences compared to the previous content of the PR. The pull request contains one new commit since
the last revision:

  Copy MemorySegment leaked from upcall

-------------

Changes:
  - all: https://git.openjdk.java.net/panama-foreign/pull/380/files
  - new: https://git.openjdk.java.net/panama-foreign/pull/380/files/972daf1f..ca06e4cf

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=380&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=panama-foreign&pr=380&range=00-01

  Stats: 56 lines in 7 files changed: 7 ins; 33 del; 16 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/380.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/380/head:pull/380

PR: https://git.openjdk.java.net/panama-foreign/pull/380