RFR: 8316694: Implement relocation of nmethod within CodeCache [v42]

[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 does not modify existing code paths and therefore does not benefit much from existing tests. New tests were created to test the new functionality
> 
> Additional Testing:
> - [x] Linux x64 fastdebug tier 1/2/3/4
> - [x] Linux aarch64 fastdebug tier 1/2/3/4

Chad Rakoczy has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 107 commits:

 - Merge remote-tracking branch 'origin/master' into JDK-8316694-Final
 - Lock nmethod::relocate behind experimental flag
 - Use CompiledICLocker instead of CompiledIC_lock
 - Fix spacing
 - Update NMethod.java with immutable data changes
 - Rename method to nm
 - Add assert before freeing immutable data
 - Reorder is_relocatable checks
 - Require caller to hold locks
 - Revert is_always_within_branch_range changes
 - ... and 97 more: https://git.openjdk.org/jdk/compare/9593730a...24c35689

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Changes: https://git.openjdk.org/jdk/pull/23573/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23573&range=41
  Stats: 1664 lines in 28 files changed: 1597 ins; 2 del; 65 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