RFR: 8358768: [vectorapi] Make VectorOperators.SUADD an Associative [v2]

[Ian Graves]

> Adding SUADD an associative operation in the Vector API. Saturated addition on fixed-width unsigned integers is provably associative.

Ian Graves has updated the pull request incrementally with one additional commit since the last revision:

  Adding masked associative tests

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26099/files
  - new: https://git.openjdk.org/jdk/pull/26099/files/0abdd644..6c8d8952

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26099&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26099&range=00-01

  Stats: 1522 lines in 34 files changed: 1522 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26099.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26099/head:pull/26099

PR: https://git.openjdk.org/jdk/pull/26099