1. Reduce duplicate stringSize code 2. Move java.lang.StringLatin1.getChars to jdk.internal.util.DecimalDigits::getCharLatin1，not only java.lang, other packages also need to use this method
------------- Commit messages: - Revert FormatItem related changes - restore StringUTF16.getChars(int,int,int,byte[]) and StringUTF16.getChars(long,int,int,byte[]) - bug fix FormatItemDecimal::prepend - fix build error - refactor & bug fix - remove unused throws - remove unused throws - refactor from #15836 - bug fix for DecimalDigits#getCharsUTF16(int, int, byte[]) - remove unused code - ... and 17 more: https://git.openjdk.org/jdk/compare/d3e82183...d4f55ddc Changes: https://git.openjdk.org/jdk/pull/15699/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15699&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8316150 Stats: 620 lines in 11 files changed: 279 ins; 303 del; 38 mod Patch: https://git.openjdk.org/jdk/pull/15699.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/15699/head:pull/15699 PR: https://git.openjdk.org/jdk/pull/15699
