RFR: 8347009: Speed ​​up parseInt and parseLong [v9]

[Shaojin Wen]

> This is an optimization for decimal Integer.parseInt and Long.parseLong, which improves performance by about 10%. The optimization includes:
> 1. Improve performance by parsing 2 numbers at a time, which has performance improvements for numbers with length >= 3.
> 2. It uses charAt(0) for the first number. Assuming that the optimization can eliminate boundary checks, this will be more friendly to parsing numbers with length 1.
> 3. It removes the reliance on the Character.digit method and eliminates the reliance on the CharacterDataLatin1#DIGITS cache array, which avoids performance degradation caused by cache misses.

Shaojin Wen has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 25 commits:

 - Merge remote-tracking branch 'upstream/master' into optim_parse_int_long_202501
   
   # Conflicts:
   #	src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
 - use &
 - from @rgiulietti
 - remove unused
 - Update src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
   
   Co-authored-by: Chen Liang <liach at openjdk.org>
 - vector digit2
 - emptyInput -> nullInput
 - use CharacterDataLatin1.instance::isDigit
 - add comments
 - reduce codeSize
 - ... and 15 more: https://git.openjdk.org/jdk/compare/f446cefe...0bacfa01

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Changes: https://git.openjdk.org/jdk/pull/22919/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22919&range=08
  Stats: 174 lines in 5 files changed: 98 ins; 26 del; 50 mod
  Patch: https://git.openjdk.org/jdk/pull/22919.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22919/head:pull/22919

PR: https://git.openjdk.org/jdk/pull/22919