[jdk19] RFR: 8288112: C2: Error: ShouldNotReachHere() in Type::typerr()

[Jatin Bhateja]

[JDK-8284960](https://bugs.openjdk.org/browse/JDK-8284960) added new vector IR nodes and target specific backend support for  Reverse Byte vector operations.  
Auto-vectorization analysis based on vector IR opcode existence and target backed implementation for existing Java SE APIs [Short/Character/Integer/Long].reverseBytes passes since both vector IR and backend support already exist for these operations. This bug fix patch handled missing scalar reverse byte IR cases in SLP optimizer to enable creation of corresponding vector IR nodes.

A new JBS issue [JDK-8290034](https://bugs.openjdk.org/browse/JDK-8290034) is created to add the missing auto-vectorization support for bit reverse operation targeting JDK mainline.

Kindly review and share your feedback.

Best Regards,
Jatin

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Commit messages:
 - 8288112: C2: Error: ShouldNotReachHere() in Type::typerr()

Changes: https://git.openjdk.org/jdk19/pull/128/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=128&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288112
  Stats: 213 lines in 9 files changed: 206 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk19/pull/128.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/128/head:pull/128

PR: https://git.openjdk.org/jdk19/pull/128