RFR: 8300647: Miscellaneous hashCode improvements in java.base [v2]

[Claes Redestad]

> Went through the jdk and found a few more places where `ArraysSupport::vectorizedHashCode` can be used, and a few where adhoc methods could be replaced with a plain call to `java.util.Arrays` equivalents. This patch addresses that.
> 
> After this, #12068, and #12077 I think we're reaching the limit of sensible direct use of `AS::vectorizedHashCode`. I've found a few places outside of java.base where `vectorizedHashCode` might be applicable, but none that seem important enough to warrant an export of this method outside of java.base.

Claes Redestad has updated the pull request incrementally with one additional commit since the last revision:

  Revert ZipFileSystem changes since it's additionally built as a library dependency and can't rely on jdk.internal

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Changes:
  - all: https://git.openjdk.org/jdk/pull/12093/files
  - new: https://git.openjdk.org/jdk/pull/12093/files/5f36ebd7..b1507e69

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12093&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12093&range=00-01

  Stats: 7 lines in 1 file changed: 2 ins; 2 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/12093.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12093/head:pull/12093

PR: https://git.openjdk.org/jdk/pull/12093