RFR: 8343829: Unify decimal and hexadecimal parsing in FloatingDecimal [v3]

[Raffaello Giulietti]

> See the JBS bug for some details.

Raffaello Giulietti has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:

 - Merge branch 'master' into 8343829
 - Minors in comments.
 - Removed repeated comment.
 - Refactoring some code and comments.
 - 8343829: Unify decimal and hexadecimal parsing in FloatingDecimal

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22737/files
  - new: https://git.openjdk.org/jdk/pull/22737/files/85709dd3..d055d0ea

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22737&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22737&range=01-02

  Stats: 1506 lines in 61 files changed: 1041 ins; 264 del; 201 mod
  Patch: https://git.openjdk.org/jdk/pull/22737.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22737/head:pull/22737

PR: https://git.openjdk.org/jdk/pull/22737