[jdk17u-dev] RFR: 8297441: Optimize Vector.rearrange over byte vectors for AVX512BW targets.

[Jatin Bhateja]

Backport of [JDK-8290322](https://bugs.openjdk.org/browse/JDK-8290322), due to multiple dependencies backport was not clean.

Patch enables wide vector byte level permutation for AVX512BW targets and benefits multiple generations of Intel's Xeon servers (SKX, CLX, CPX) prior to Ice lake which provides a direct HW instruction (VPERMB). JIT instruction sequence emitted in this case is specific to Vector.rearrange API, hence the scope of the patch is limited to VectorAPIs which is an incubating module currently.

Vector API jtreg test suite contains multiple tests cases for ByteVector.SPECIES_512 to extensively tests the patch.

Original patch review was done with [PR 9498](https://github.com/openjdk/jdk/pull/9498)

-------------

Commit messages:
 - 8297441: Optimize Vector.rearrange over byte vectors for AVX512BW targets.

Changes: https://git.openjdk.org/jdk17u-dev/pull/917/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=917&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297441
  Stats: 193 lines in 6 files changed: 188 ins; 4 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/917.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/917/head:pull/917

PR: https://git.openjdk.org/jdk17u-dev/pull/917