RFR: 8332029: Provide access to initial value of stderr via JavaLangAccess

[Alan Bateman]

In preparation for JEP 471 and JEP 472, provide access to the initial value of System.err from JavaLangAccess. The initial value of System.in is already exposed to code in java.base with this shared secret.

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/19171/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19171&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332029
  Stats: 30 lines in 3 files changed: 20 ins; 5 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/19171.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19171/head:pull/19171

PR: https://git.openjdk.org/jdk/pull/19171