Backport of AOT jcmd/mxbean to JDK 25

[ioi.lam at oracle.com]

In today's Leyden meeting, we decided to backport the AOT jcmd/mxbean to 
JDK 25.

I did a little research of backporting JBS issues that need a CSR.

- The general process is described in 
https://wiki.openjdk.org/spaces/csr/pages/32342047/CSR+FAQs

- An existing example of a backport that needed a CSR:

    - Backport: https://bugs.openjdk.org/browse/JDK-8304943
    - CSR: https://bugs.openjdk.org/browse/JDK-8304944

- I created the backport issues and made a verbatim copy of the original 
CSRs

mxbean:

https://bugs.openjdk.org/browse/JDK-8376156
https://bugs.openjdk.org/browse/JDK-8376157

jcmd:
https://bugs.openjdk.org/browse/JDK-8376154
https://bugs.openjdk.org/browse/JDK-8376155

To Mat, I have assigned the above issue to you. Could you take over from 
here?

Thanks

- Ioi