RFR: 8316694: Implement relocation of nmethod within CodeCache [v3]

[Chad Rakoczy]

> This PR introduces a new function to replace nmethods, addressing [JDK-8316694](https://bugs.openjdk.org/browse/JDK-8316694). It enables the creation of new nmethods from existing ones, allowing method relocation in the code heap and supporting [JDK-8328186](https://bugs.openjdk.org/browse/JDK-8328186).
> 
> When an nmethod is replaced, a deep copy is performed. The corresponding Java method is updated to reference the new nmethod, while the old one is marked as unused. The garbage collector handles final cleanup and deallocation.
> 
> This change does not modify existing code paths and therefore does not benefit much from existing tests. New tests were created and confirmed to pass on x64/aarch64 for slowdebug/fastdebug/release.

Chad Rakoczy has updated the pull request incrementally with one additional commit since the last revision:

  Share immutable data between copied nmethods

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Changes:
  - all: https://git.openjdk.org/jdk/pull/23573/files
  - new: https://git.openjdk.org/jdk/pull/23573/files/69d941b4..80734cd3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23573&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23573&range=01-02

  Stats: 32 lines in 2 files changed: 19 ins; 4 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/23573.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23573/head:pull/23573

PR: https://git.openjdk.org/jdk/pull/23573