RFR: 8361209: (bf) Use CharSequence::getChars for StringCharBuffer bulk get methods [v3]

[Brian Burkhalter]

> For `CharBuffer`s created from a `CharSequence`, use `CharSequence.getChars` to perform bulk gets instead of successively copying single characters.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8361209: Override getArray instead of API methods; modify absolute bulk put to use getArray for StringCharBuffer

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26251/files
  - new: https://git.openjdk.org/jdk/pull/26251/files/fb5ea838..dce00b5a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26251&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26251&range=01-02

  Stats: 38 lines in 3 files changed: 10 ins; 22 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/26251.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26251/head:pull/26251

PR: https://git.openjdk.org/jdk/pull/26251