RFR: 8354724: Methods in java.io.Reader to read all characters and all lines [v17]

[Brian Burkhalter]

> Implement the requested methods and add a test thereof.

Brian Burkhalter has updated the pull request incrementally with two additional commits since the last revision:

 - Update src/java.base/share/classes/java/io/Reader.java
   
   8354724: Apply suggested changes for readAllLines.
   
   Co-authored-by: Roger Riggs <Roger.Riggs at Oracle.com>
 - Update src/java.base/share/classes/java/io/Reader.java
   
   8354724: Apply suggested changes for readAllAsString.
   
   Co-authored-by: Roger Riggs <Roger.Riggs at Oracle.com>

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24728/files
  - new: https://git.openjdk.org/jdk/pull/24728/files/983aeb50..a4cf9224

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24728&range=16
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24728&range=15-16

  Stats: 22 lines in 1 file changed: 9 ins; 0 del; 13 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