RFR: JDK-8301810: Bug in doctree DocCommentTester.compress

Fri Feb 3 20:25:53 UTC 2023

Please review a minor but long-standing bug in the code to "compress" long strings in the `doctree` `DocCommentTester` class.

The primary change is in `DocCommentTester`, to fix the code, and make it somewhat more robust.  The change does break some golden output, in comments and files, so advantage is taken to increase the max size of compressed strings.

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Commit messages:
 - JDK-8301810: Bug in doctree DocCommentTester.compress

Changes: https://git.openjdk.org/jdk/pull/12418/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12418&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301810
  Stats: 22 lines in 13 files changed: 4 ins; 0 del; 18 mod
  Patch: https://git.openjdk.org/jdk/pull/12418.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12418/head:pull/12418

PR: https://git.openjdk.org/jdk/pull/12418