RFR: 8369881: C2: Unexpected node in SuperWord truncation: ReverseBytesS, ReverseBytesUS

[Emanuel Peter]

The fuzzer found the `ReverseByteS` case, and I checked all other `*.reverseBytes`, and found a failure with `Character.reverseBytes` as well.

Adding them to the list, and added tests for both.

Note, this is just another 2 boxes checked, there were many similar ones fixed, or on the way:
https://github.com/openjdk/jdk/pull/26827
https://github.com/openjdk/jdk/pull/26334
https://github.com/openjdk/jdk/pull/26494
https://github.com/openjdk/jdk/pull/26423

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Commit messages:
 - fix ReverseBytesUS as well
 - fix for ReverseBytesS
 - JDK-8369881

Changes: https://git.openjdk.org/jdk/pull/27819/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27819&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8369881
  Stats: 54 lines in 2 files changed: 53 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27819.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27819/head:pull/27819

PR: https://git.openjdk.org/jdk/pull/27819