RFR: 8316115: Parallel: Fix -Wconversion warnings around NUMA node ID

[Aleksey Shipilev]

On Tue, 12 Sep 2023 11:48:57 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

> Essentially same as https://github.com/openjdk/jdk/pull/15541, but for Parallel.

See multiple failures in GHA :)

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Changes requested by shade (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15682#pullrequestreview-1622160586