RFR: 8271515: Integration of JEP 417: Vector API (Third Incubator) [v3]

[Paul Sandoz]

> This PR improves the performance of vector operations that accept masks on architectures that support masking in hardware, specifically Intel AVX512 and ARM SVE.
> 
> On architectures that do not support masking in hardware the same technique as before is applied to most operations, specifically composition using blend.
> 
> Masked loads/stores are a special form of masked operation that require additional care to ensure out-of-bounds access throw exceptions. The range checking has not been fully optimized and will require further work.
> 
> No API enhancements were required and only a few additional tests were needed.

Paul Sandoz has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains seven commits:

 - Merge branch 'master' into JDK-8271515-vector-api
 - Apply patch from https://github.com/openjdk/panama-vector/pull/152
 - Apply patch from https://github.com/openjdk/panama-vector/pull/142
 - Apply patch from https://github.com/openjdk/panama-vector/pull/139
 - Apply patch from https://github.com/openjdk/panama-vector/pull/151
 - Add new files.
 - 8271515: Integration of JEP 417: Vector API (Third Incubator)

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Changes: https://git.openjdk.java.net/jdk/pull/5873/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5873&range=02
  Stats: 21998 lines in 106 files changed: 16227 ins; 2077 del; 3694 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5873.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5873/head:pull/5873

PR: https://git.openjdk.java.net/jdk/pull/5873