RFR: 8316587: Use ArraysSupport.vectorizedHashCode in Utf8EntryImpl [v2]

[Chen Liang]

> Like #12077, this uses JDK's internal utilities to speed up ASCII reading in Class files, where most identifiers, from conventions to attribute names, are ASCII. See the JBS issue for more in-depth explanations.
> 
> Before: (Master)
> 
> Benchmark                         Mode  Cnt    Score   Error  Units
> ReadMetadata.jdkReadMemberNames  thrpt    4  167.623 ± 8.522  ops/s
> 
> 
> After: (This patch, first revision)
> 
> Benchmark                         Mode  Cnt    Score   Error  Units
> ReadMetadata.jdkReadMemberNames  thrpt    4  175.908 ± 4.766  ops/s

Chen Liang has updated the pull request incrementally with one additional commit since the last revision:

  Fix logical bug with char array filling

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15837/files
  - new: https://git.openjdk.org/jdk/pull/15837/files/d0ce1181..6f5e3d72

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15837&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15837&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15837.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15837/head:pull/15837

PR: https://git.openjdk.org/jdk/pull/15837