RFR: 8319875: Add macOS implementation for jcmd System.map [v16]

[Thomas Stuefe]

On Mon, 9 Dec 2024 22:46:57 GMT, Simon Tooke <stooke at openjdk.org> wrote:

>> This is a port of #16301  to macOS.
>> 
>> System.map and System.dump_map are implemented using the macOS API and provide roughly the same information in the same format. Most of the heavy lifting was implemented by @tstuefe in https://github.com/openjdk/jdk/pull/16301 - this PR adds the macOS implementation and enables the common code for macOS 64 bit.
>> 
>> The System.map tests are also reworked to be cleaner for the three implementations.
>> 
>> [sample output using G1GC](https://github.com/user-attachments/files/17558064/g1_map.txt)
>> [sample output using ZGC](https://github.com/user-attachments/files/17558067/zgc_map.txt)
>
> Simon Tooke has updated the pull request incrementally with one additional commit since the last revision:
> 
>   fix crash due to uninitilized pointer

BTW make sure you merge and test again before integrating. Your branch is quite old. In fact, you should merge upstream often (The rule with merge vs rebase is: you merge after the patch has been un-drafted und RFR mail has been set out; before that, you can rebase).

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

PR Comment: https://git.openjdk.org/jdk/pull/20953#issuecomment-2531503100