[jdk21u-dev] RFR: 8337066: Repeated call of StringBuffer.reverse with double byte string returns wrong result

[Goetz Lindenmaier]

I backport this for parity with 21.0.6-oracle.

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Commit messages:
 - Backport cd61f97c2de94d19c0101c51bde143001078c89f

Changes: https://git.openjdk.org/jdk21u-dev/pull/1116/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1116&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8337066
  Stats: 58 lines in 2 files changed: 58 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1116.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1116/head:pull/1116

PR: https://git.openjdk.org/jdk21u-dev/pull/1116