[jdk18] RFR: 8281713: [BACKOUT] AArch64: Implement string_compare intrinsic in SVE

[Tobias Hartmann]

We observed several failures on macosx aarch64 after integration of [JDK-8275448](https://bugs.openjdk.java.net/browse/JDK-8275448). I could reliably reproduce [JDK-8281512](https://bugs.openjdk.java.net/browse/JDK-8281512) with JDK 18 b25-1665 (the first build with [JDK-8275448](https://bugs.openjdk.java.net/browse/JDK-8275448) containing no other changes) but **not** with JDK 18 b25-1664 (the build just before integration). Also, I could reliably reproduce the issue with mainline but **not** with the string compare intrinsic disabled. I think this is enough evidence to prove that [JDK-8275448](https://bugs.openjdk.java.net/browse/JDK-8275448) is the root cause of the failures.

Given that we don't fully understand which part of this fix is causing the issue and how (it might be a side effect that triggers a bug in the build toolchain or adlc), I propose to backout the change. The backout applies cleanly, approval is pending.

Thanks,
Tobias

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Commit messages:
 - Revert "8275448: [REDO] AArch64: Implement string_compare intrinsic in SVE"

Changes: https://git.openjdk.java.net/jdk18/pull/116/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk18&pr=116&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8281713
  Stats: 423 lines in 9 files changed: 0 ins; 412 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk18/pull/116.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk18 pull/116/head:pull/116

PR: https://git.openjdk.java.net/jdk18/pull/116