[vectorIntrinsics] RFR: 8253585: Add basic vector mask implementation for Arm SVE

[Xiaohong Gong]

Summary: Add the SVE match rule support for vector mask ops.

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Currently the vector mask related operations like vector mask load/store, vector mask compare and vector blend are not supported for Arm SVE. This patch adds the basic backend implementation for them.

BTW, this is a basic version for vector mask operations that does not use the SVE predicate features. And we will make it happen in future.

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Commit messages:
 - 8253585: Add basic vector mask implementation for Arm SVE

Changes: https://git.openjdk.java.net/panama-vector/pull/20/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=20&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253585
  Stats: 1177 lines in 8 files changed: 1000 ins; 20 del; 157 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/20.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/20/head:pull/20

PR: https://git.openjdk.java.net/panama-vector/pull/20