[foreign-abi] RFR: Merge foreign-memaccess [v2]

[J.Duke]

> Hi all,
> 
> this is an _automatically_ generated pull request to notify you that there is 1 commit from the branch
> `foreign-memaccess`that can **not** be merged into the branch `foreign-abi`:
> The following file contains merge conflicts:
> 
> - test/micro/org/openjdk/bench/jdk/incubator/foreign/points/support/PanamaPoint.java
> 
> All Committers in this [project](https://openjdk.java.net/census#Optional[panama]) have access to my [personal
> fork](https://github.com/openjdk-bot/panama-foreign) and can therefore help resolve these merge conflicts (you may want
> to coordinate who should do this). The following paragraphs will give an example on how to solve these merge conflicts
> and push the resulting merge commit to this pull request. The below commands should be run in a local clone of your
> [personal fork](https://wiki.openjdk.java.net/display/skara#Skara-Personalforks) of the
> [openjdk/panama-foreign](https://github.com/openjdk/panama-foreign) repository.  # Ensure target branch is up to date $
> git checkout foreign-abi $ git pull https://github.com/openjdk/panama-foreign foreign-abi
> 
> # Fetch and checkout the branch for this pull request
> $ git fetch https://github.com/openjdk-bot/panama-foreign +45:openjdk-bot-45
> $ git checkout openjdk-bot-45
> 
> # Merge the target branch
> $ git merge foreign-abi
> 
> When you have resolved the conflicts resulting from the `git merge` command above, run the following commands to create
> a merge commit:
> $ git add paths/to/files/with/conflicts
> $ git commit -m 'Merge foreign-memaccess'
> 
> 
> When you have created the merge commit, run the following command to push the merge commit to this pull request:
> 
> $ git push https://github.com/openjdk-bot/panama-foreign openjdk-bot-45:45
> 
> _Note_: if you are using SSH to push commits to GitHub, then change the URL in the above `git push` command accordingly.
> 
> Thanks,
> J. Duke

J. Duke has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains
three commits:

 - Fixup references to MemorySegment::baseAddress
 - Merge branch 'foreign-abi' into openjdk-bot-45
 - 8249790: Add Addressable abstraction
   
   Reviewed-by: sundar, jvernee

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

Changes: https://git.openjdk.java.net/panama-foreign/pull/253/files
 Webrev: https://webrevs.openjdk.java.net/panama-foreign/253/webrev.01
  Stats: 424 lines in 50 files changed: 53 ins; 5 del; 366 mod
  Patch: https://git.openjdk.java.net/panama-foreign/pull/253.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-foreign pull/253/head:pull/253

PR: https://git.openjdk.java.net/panama-foreign/pull/253