RFR: 8284922: Fix some doc-comment issues on methods with package access in JDK API

[Pavel Rappo]

People rarely include JDK elements with package access in a javadoc run. That is why bugs in those elements' doc comments tend to remain unnoticed.

There are many more bugs in the doc comments of the JDK elements with the package access than are addressed by this PR; I only included the simplest ones.

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Commit messages:
 - Update copyright years
 - Initial commit

Changes: https://git.openjdk.java.net/jdk/pull/8267/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8267&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284922
  Stats: 6 lines in 3 files changed: 1 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8267.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8267/head:pull/8267

PR: https://git.openjdk.java.net/jdk/pull/8267