RFR: 8342677: Add IR validation tests for newly added saturated vector add / sub operations

[Jatin Bhateja]

This is a follow up PR to https://github.com/openjdk/jdk/pull/20507
It adds IR validation tests for newly added saturated vector add / sub operations.

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Commit messages:
 - Use feature check
 - Update test tags
 - Merge branch 'master' of http://github.com/openjdk/jdk into JDK-8342677
 - 8342677: Add IR validation tests for newly added saturated add / sub vector operations

Changes: https://git.openjdk.org/jdk/pull/21603/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21603&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342677
  Stats: 514 lines in 2 files changed: 514 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21603.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21603/head:pull/21603

PR: https://git.openjdk.org/jdk/pull/21603