RFR: 8254884: Make sure jvm does not crash with Arm SVE and Vector API

[Ningsheng Jian]

Currently we have not implemented all Arm SVE code generation for Vector API specific nodes. To make sure hotspot does
not crash with bad AD file (as NEON has implemented them), we simply add those OPs to unsupported op list.

This is the port and minor cleanup of JDK-8253211 in repo-panama: https://github.com/openjdk/panama-vector/pull/7 with
Op_VectorUnbox (not for codegen) and Op_VectorMaskWrapper (actually unused node. dead code?) removed from the
unsupported op list and Op_VectorLoadConst added.

Test: tier1-3 on AArch64 and x86_64 as well as Vector API tests on AArch64 SVE.

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Commit messages:
 - 8254884: Make sure jvm does not crash with Arm SVE and Vector API

Changes: https://git.openjdk.java.net/jdk/pull/726/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=726&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8254884
  Stats: 130 lines in 4 files changed: 117 ins; 0 del; 13 mod
  Patch: https://git.openjdk.java.net/jdk/pull/726.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/726/head:pull/726

PR: https://git.openjdk.java.net/jdk/pull/726