[vectorIntrinsics] RFR: 8265312: Unsigned comparison operators

[Paul Sandoz]

Add unsigned comparison operators to VectorOperators and add intrinsic support on x64.

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Commit messages:
 - Remove trailing WS
 - Fix merge.
 - Fix typo.
 - Sync constant names.
 - Merge pull request #5 from sviswa7/unsigned-comparison-operators
 - Merge with vectorIntrinsics
 - Use constants
 - Merge pull request #4 from sviswa7/unsigned-comparison-operators
 - review comments
 - Add individual unsigned comparison enum consts in BoolTest
 - ... and 8 more: https://git.openjdk.java.net/panama-vector/compare/d6eb1b8b...0386036d

Changes: https://git.openjdk.java.net/panama-vector/pull/68/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=68&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8265312
  Stats: 8359 lines in 95 files changed: 7627 ins; 116 del; 616 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/68.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/68/head:pull/68

PR: https://git.openjdk.java.net/panama-vector/pull/68