RFR: 8316098: Revise signature of numa_get_leaf_groups

[Coleen Phillimore]

On Mon, 18 Sep 2023 12:22:11 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Simple refactoring to better reflect NUMA node id is non-negative using unsigned type.
> 
> More cleanup can possibly be done to avoid the use of `checked_cast` in `os_windows.cpp`, but since the NUMA code in Windows is unreachable (JDK-8244065), I went to for the smallest diff there in order to avoid adding more untested code.

Looks good to me.

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15786#pullrequestreview-1644136515