[vectorIntrinsics] RFR: 8282915: Add new vector operation for reverse bits operation

[Smita Kamath]

Hi,

I've added support for new vector operations for reversing bits of integral vector types(Byte/Short/Integer/Long).
Currently, this PR addresses only Java changes for reverse operation. I've also updated the test framework.
Do review and share feedback.

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Commit messages:
 - Fixed indentation, modified code
 - fixed indentation
 - reverse bits Java implementation

Changes: https://git.openjdk.java.net/panama-vector/pull/178/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=178&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282915
  Stats: 2056 lines in 81 files changed: 2056 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/178.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/178/head:pull/178

PR: https://git.openjdk.java.net/panama-vector/pull/178