[jdk21u-dev] RFR: 8319817: Charset constructor should make defensive copy of aliases [v2]

[Todd V. Jonker]

> Clean backport.
> 
> Additional testing:
> - [x] New regression test fails without the fix, passes with it
> - [x] linux-x86_64-server-release: `JTREG_KEYWORDS="!headful & !external-dep & !printer" make test TEST=all`
>     * These tests fail repeatedly, but also fail on `master`:
>         * `build/AbsPathsInImage.java`
>         * `java/nio/channels/FileChannel/directio/DirectIOTest.java`

Todd V. Jonker 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 two additional commits since the last revision:

 - Merge branch 'master' into charset-ctor for testing
 - Backport d6d7bdc7748c10963c3e58c0287b2472646bf36f

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

Changes:
  - all: https://git.openjdk.org/jdk21u-dev/pull/841/files
  - new: https://git.openjdk.org/jdk21u-dev/pull/841/files/5a733371..92503f50

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=841&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=841&range=00-01

  Stats: 6051 lines in 152 files changed: 2806 ins; 1929 del; 1316 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/841.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/841/head:pull/841

PR: https://git.openjdk.org/jdk21u-dev/pull/841