RFR: 8341975: Unable to set encoding for IO.println, IO.print and IO.readln [v4]

[Naoto Sato]

> Changing the charset initialization of `java.io.Console` class, which is the basis of `java.io.IO`, so that it would behave the same way as `System.out` wrt encoding. This change will also have the capability to override the default charset used in `IO` methods with `stdout.encoding` system property. A corresponding CSR has also been drafted.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  Reflects review comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21569/files
  - new: https://git.openjdk.org/jdk/pull/21569/files/9000280b..805365c6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21569&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21569&range=02-03

  Stats: 5 lines in 1 file changed: 1 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/21569.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21569/head:pull/21569

PR: https://git.openjdk.org/jdk/pull/21569