RFR: 8354724: Methods in java.io.Reader to read all characters and all lines [v25]

[Brian Burkhalter]

> Implement the requested methods and add a test thereof.

Brian Burkhalter 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 29 additional commits since the last revision:

 - 8354724: Update API notes
 - Merge
 - 8354724: Revert previous commit and remove first comma in the change
 - 8354724: Improve verbiage about I/O errors
 - 8354724: Replace getChars in previous commit with subSequence
 - 8354724: Improve readAllAsString method of Reader returned by Reader.of
 - 8354724: Change readAllCharsAsString as suggested; move test to proper location
 - 8354724: "stream" -> "reader"
 - 8354724: Attempt to further improve verbiage
 - Merge
 - ... and 19 more: https://git.openjdk.org/jdk/compare/bcf1bca6...f9c732eb

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24728/files
  - new: https://git.openjdk.org/jdk/pull/24728/files/0880af29..f9c732eb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24728&range=24
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24728&range=23-24

  Stats: 66091 lines in 1204 files changed: 34984 ins; 23883 del; 7224 mod
  Patch: https://git.openjdk.org/jdk/pull/24728.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24728/head:pull/24728

PR: https://git.openjdk.org/jdk/pull/24728