RFR: 8364936: Shenandoah: Switch nmethod entry barriers to conc_instruction_and_data_patch [v3]

[Cesar Soares Lucas]

> Hi all,
> 
> This pull request contains a backport of commit [81a1e8e1](https://github.com/openjdk/jdk/commit/81a1e8e1363446de499a59fc706221efde12dd86) from the [openjdk/jdk](https://git.openjdk.org/jdk) repository.
> 
> The commit being backported was authored by Cesar Soares Lucas on 8 Sep 2025 and was reviewed by Fei Yang, Dingli Zhang, Kelvin Nilsen and William Kemper.
> 
> I had to manually resolve a merge conflict in `TestHotSpotVMConfig.java` because the original patch modified a region of the file that is not present in this repository version of the same file.
> 
> Thanks!

Cesar Soares Lucas has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  Revert some changes due to non-ZGC using the old patching type.

-------------

Changes:
  - all: https://git.openjdk.org/shenandoah-jdk21u/pull/218/files
  - new: https://git.openjdk.org/shenandoah-jdk21u/pull/218/files/af29f617..0020610c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=218&range=02
 - incr: https://webrevs.openjdk.org/?repo=shenandoah-jdk21u&pr=218&range=01-02

  Stats: 11 lines in 5 files changed: 9 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/shenandoah-jdk21u/pull/218.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk21u.git pull/218/head:pull/218

PR: https://git.openjdk.org/shenandoah-jdk21u/pull/218