RFR: 8293841: RISC-V: Implementation of Foreign Function & Memory API (Preview) [v6]

[Feilong Jiang]

> Add experimental Foreign Function & Memory API support for RISC-V.
> 
> For details of the FFM API RISC-V port please refer to [JBS issue](https://bugs.openjdk.org/browse/JDK-8293841)
> 
> Testing:
> 
> - [x] jdk_foreign with release/fastdebug build on linux-riscv64
> - [x] jdk_foreign with release/fastdebug build on linux-x64
> - [x] jdk_foreign with release/fastdebug build on linux-aarch64

Feilong Jiang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 10 additional commits since the last revision:

 - fix comment & code adjustment
 - Merge branch 'master' of https://github.com/openjdk/jdk into JDK-8293841-foreign-api-riscv
 - fix callArranger
 - fix callArranger
 - fix build
 - Merge branch 'master' of https://github.com/openjdk/jdk into JDK-8293841-foreign-api-riscv
 - code adjustment and remove unnecessary static
 - sync with JDK-8296477
 - sync with JDK-8295044
 - JDK-8293841: RISC-V: Implementation of Foreign Function & Memory API (Preview)

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11004/files
  - new: https://git.openjdk.org/jdk/pull/11004/files/fee96ae8..be0826db

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11004&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11004&range=04-05

  Stats: 5077 lines in 204 files changed: 3274 ins; 964 del; 839 mod
  Patch: https://git.openjdk.org/jdk/pull/11004.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11004/head:pull/11004

PR: https://git.openjdk.org/jdk/pull/11004