RFR: 8363929: G1: Add G1 prefix to various G1 specific global locks

[Thomas Schatzl]

Hi all,

  please review this renaming of a few G1 specific locks to have a G1 prefix to make it clear that they should not be used elsewhere.

Testing: local compilation, gha

Thanks,
  Thomas

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Commit messages:
 - 8363929

Changes: https://git.openjdk.org/jdk/pull/26444/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26444&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8363929
  Stats: 59 lines in 9 files changed: 6 ins; 6 del; 47 mod
  Patch: https://git.openjdk.org/jdk/pull/26444.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26444/head:pull/26444

PR: https://git.openjdk.org/jdk/pull/26444