[jdk21u-dev] RFR: 8331572: Allow using OopMapCache outside of STW GC phases

[Aleksey Shipilev]

WIP. Unclean backport to improve GC and general stack walk performance when walking interpreted frames.

The point of uncleanliness comes from the way we hook up the cleanup notifications to Service Thread. In later JDKs, [JDK-8329488](https://bugs.openjdk.org/browse/JDK-8329488) made Service Thread wake up regularly to do various cleanups. In JDK 21, we still need to hook up the clean up to the "usual" place in safepoint epilog.

Additional testing:
 - [x] Linux x86_64 server fastdebug, `all`

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Commit messages:
 - Backport d999b81e7110751be402012e1ed41b3256f5895e

Changes: https://git.openjdk.org/jdk21u-dev/pull/610/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=610&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331572
  Stats: 114 lines in 12 files changed: 72 ins; 14 del; 28 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/610.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/610/head:pull/610

PR: https://git.openjdk.org/jdk21u-dev/pull/610