RFR: 8311130: AArch64: Sync SVE related CPU features with VM options

[Pengfei Li]

As discussed in PR #14533, keeping AArch64 flag `UseSVE` and its related CPU features in sync helps to simplify rules in IR tests. In this patch, we mask SVE related CPU features off if specified SVE level in VM option is lower than the hardware supported. Also, to support this change, we move the features string construction to the end of the `initialize()` function.

We also revert IR rule changes in PR #14533 and fix some code styles. We tested almost full jtreg on SVE, SVE2 and non-SVE CPUs and no new issue is found after this patch.

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Commit messages:
 - 8311130: AArch64: Sync SVE related CPU features with VM options

Changes: https://git.openjdk.org/jdk/pull/14897/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14897&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8311130
  Stats: 151 lines in 3 files changed: 114 ins; 15 del; 22 mod
  Patch: https://git.openjdk.org/jdk/pull/14897.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14897/head:pull/14897

PR: https://git.openjdk.org/jdk/pull/14897