[jdk11u] RFR: 8331750: [11u] JDK-8259530 is not backported correctly to 11u

[Kimura Yukihiro]

This pull request ports a fix from jdk11u-dev.
I have confirmed that the fix passes the following tests:
 - test/langtools/jdk/javadoc/doclet/testLegalNotices/TestLegalNotices.java
 - All langtool tests
Could someone please review the fix?

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Commit messages:
 - 8331750:[11u] JDK-8259530 is not backported correctly to 11u

Changes: https://git.openjdk.org/jdk11u/pull/92/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk11u&pr=92&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331750
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk11u/pull/92.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u.git pull/92/head:pull/92

PR: https://git.openjdk.org/jdk11u/pull/92