RFR: 8271515: Integration of JEP 417: Vector API (Third Incubator) [v6]

[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 incrementally with two additional commits since the last revision:

 - Merge pull request #1 from nsjian/JDK-8271515
   
   Address AArch64 review comments from Nick.
 - Address review comments from Nick.

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5873/files
  - new: https://git.openjdk.java.net/jdk/pull/5873/files/9945ce8d..2919465a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5873&range=05
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5873&range=04-05

  Stats: 35 lines in 5 files changed: 3 ins; 2 del; 30 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