RFR: Bring jdk20 branch in sync with panama branch [v3]

Wed Mar 22 12:18:52 UTC 2023

> This PR brings fixes from `panama` branch back to the `jdk20` branch.
> We are doing this as part of getting ready to start shipping binary snapshot of the jdk20 version of jextract.

Maurizio Cimadamore has updated the pull request incrementally with one additional commit since the last revision:

  More README fixes

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

Changes:
  - all: https://git.openjdk.org/jextract/pull/114/files
  - new: https://git.openjdk.org/jextract/pull/114/files/9b4f33e3..a7109b2f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jextract&pr=114&range=02
 - incr: https://webrevs.openjdk.org/?repo=jextract&pr=114&range=01-02

  Stats: 13 lines in 1 file changed: 3 ins; 0 del; 10 mod
  Patch: https://git.openjdk.org/jextract/pull/114.diff
  Fetch: git fetch https://git.openjdk.org/jextract.git pull/114/head:pull/114

PR: https://git.openjdk.org/jextract/pull/114