https://openjdk.java.net/jeps/389
See also
https://inside.java/2020/12/21/podcast-010/
And the official tool jextract
https://github.com/openjdk/panama-foreign/blob/2d966367a7c9e0cf543ab0cdc159cb3d4ef8f165/doc/panama_jextract.md

Openjdk 16 is meant to be released next month :)

Unrelated but interesting:
https://openjdk.java.net/jeps/338