[jdk19] RFR: 8287794: Reverse*VNode::Identity problem

[Jatin Bhateja]

Hi All,

- This bug fix patch fixes a missing case during reverse[bits|bytes] identity transformation.
- Unlike AARCH64(SVE),  X86(AVX512) ISA has no direct instruction to reverse[bits|bytes] of a vector lane hence a predicated operation is supported through blend instruction.
- New IR framework based tests have been added for transforms relevant to AVX2, AVX512 and SVE.

Kindly review and share your feedback.

Best Regards,
Jatin

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Commit messages:
 - 8287794: Reverse*VNode::Identity problem

Changes: https://git.openjdk.org/jdk19/pull/153/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=153&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8287794
  Stats: 414 lines in 3 files changed: 412 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk19/pull/153.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/153/head:pull/153

PR: https://git.openjdk.org/jdk19/pull/153