[jdk25u-dev] RFR: 8364936: Shenandoah: Switch nmethod entry barriers to conc_instruction_and_data_patch

[Aleksey Shipilev]

Improves Shenandoah performance on some workloads.

Additional testing:
 - [x] Linux AArch64 server fastdebug, `hotspot_gc_shenandoah`
 - [x] Linux AArch64 server fastdebug, `all` with `-XX:+UseShenandoahGC`

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Commit messages:
 - Backport 81a1e8e1363446de499a59fc706221efde12dd86

Changes: https://git.openjdk.org/jdk25u-dev/pull/129/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=129&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364936
  Stats: 28 lines in 12 files changed: 0 ins; 19 del; 9 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/129.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/129/head:pull/129

PR: https://git.openjdk.org/jdk25u-dev/pull/129