[jdk21u-dev] RFR: 8350412: [21u] AArch64: Ambiguous frame layout leads to incorrect traces in JFR

[Dmitry Chuyko]

This change fixes incorrect stack traces sometimes reported by JFR (non-deterministic stack walking). It is technically a clean backport of 'Make the anchor frame walkable' changes of aarch64_enc_java_to_runtime() from https://github.com/openjdk/jdk/pull/21565/files#diff-018aa61d1a7aafcf70a535fcd40a318a4bd6511fd40ac39ce4be90cc52216749

I propose to cherry pick those into older releases after JDK 24 is out, starting from 21u.

Testing: tier1,2 on linux-aarch64.

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Commit messages:
 - Backport 'Make the anchor frame walkable' in aarch64.ad from JDK-8338383

Changes: https://git.openjdk.org/jdk21u-dev/pull/1418/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1418&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8350412
  Stats: 7 lines in 1 file changed: 3 ins; 4 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1418.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1418/head:pull/1418

PR: https://git.openjdk.org/jdk21u-dev/pull/1418