[jdk17u-dev] RFR: 8256844: Make NMT late-initializable

[Vladimir Kempik]

Please review this backport to jdk17u-dev
Doesn't apply clean because of JDK-8280940 backport which introduced the same patch into test_os.cpp

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Commit messages:
 - 8256844: Make NMT late-initializable

Changes: https://git.openjdk.org/jdk17u-dev/pull/496/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=496&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8256844
  Stats: 1820 lines in 24 files changed: 1391 ins; 390 del; 39 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/496.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/496/head:pull/496

PR: https://git.openjdk.org/jdk17u-dev/pull/496