RFR: 8304265: Implementation of Foreign Function and Memory API (Third Preview) [v10]

[Per Minborg]

> API changes for the FFM API (third preview)
> 
> Specdiff:
> https://cr.openjdk.org/~pminborg/panama/21/v1/specdiff/overview-summary.html
> 
> Javadoc:
> https://cr.openjdk.org/~pminborg/panama/21/v1/javadoc/java.base/module-summary.html

Per Minborg has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 22 commits:

 - Merge with master
 - Make fallbacklinker.c consistent with downcallLinker.cpp
 - Add bug number
 - Use @return
 - Update Linker.downcallHandle() javadoc
 - Fix typos in Arena
 - Make checking method handle zero case
 - Add snippet to Linker.Option.captureStateLayout()
 - Apply RISCV port patch
 - Improve javadocs for Linker::captureStateLayout
 - ... and 12 more: https://git.openjdk.org/jdk/compare/cddaf686...bc29c6fc

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

Changes: https://git.openjdk.org/jdk/pull/13079/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13079&range=09
  Stats: 13027 lines in 267 files changed: 5006 ins; 6015 del; 2006 mod
  Patch: https://git.openjdk.org/jdk/pull/13079.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13079/head:pull/13079

PR: https://git.openjdk.org/jdk/pull/13079