RFR: 8368251: Parallel: Refactor lgrp_id used in MutableNUMASpace

[Joel Sikström]

Hello,

There are multiple cases which handle if the locality group (lgrp) id is negative (-1) in Parallel, specifically in MutableNUMASpace. -1 was historically used to indicate that the hardware topology has changed and that the lgrp id needs to be updated. This is no longer the case, since HotSpot doesn't support CPU/NUMA hotplugging, and the last piece of code setting the lgrp id to -1 was removed in [JDK-8301149](https://bugs.openjdk.org/browse/JDK-8301149).

I propose we simplify the code a bit by not handling edge cases where the lgrp id is -1 and removing os::numa_has_group_homing(), which always return false

Testing:
 * Running through Oracle's tier 1-4
 * Local NUMA testing tier1-4 with `-XX:+UseParallelGC -XX:+UseNUMA`

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Commit messages:
 - 8368251: Parallel: Refactor lgrp_id used in MutableNUMASpace

Changes: https://git.openjdk.org/jdk/pull/27424/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27424&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368251
  Stats: 117 lines in 10 files changed: 9 ins; 88 del; 20 mod
  Patch: https://git.openjdk.org/jdk/pull/27424.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27424/head:pull/27424

PR: https://git.openjdk.org/jdk/pull/27424