RFR: 8337167: StringSize deduplication [v2]

[Shaojin Wen]

> Integer.stringSize and Long.stringSize are used not only in java.lang, but also in other places. We put stringSize in DecimalDigits to reduce duplicate code and the use of JLA.

Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:

  remove unused Integer.stringSize & Long.stringSize

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20322/files
  - new: https://git.openjdk.org/jdk/pull/20322/files/752279f0..a3045712

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20322&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20322&range=00-01

  Stats: 30 lines in 2 files changed: 0 ins; 30 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20322.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20322/head:pull/20322

PR: https://git.openjdk.org/jdk/pull/20322