RFR: 8343486: Remove unnecessary @SuppressWarnings annotations and -Xlint:-foo options [v2]

[Archie Cobbs]

> Please review this patch which removes unnecessary `@SuppressWarnings` annotations and `-Xlint:-foo` options.

Archie Cobbs 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 four additional commits since the last revision:

 - Update copyright years.
 - Merge branch 'master' into SuppressWarningsCleanup-build
 - Merge branch 'master' into SuppressWarningsCleanup-build
 - Remove unnecessary @SuppressWarnings annotations and -Xlint:-key flags.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/21859/files
  - new: https://git.openjdk.org/jdk/pull/21859/files/389dd678..79f5a620

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21859&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21859&range=00-01

  Stats: 3227 lines in 125 files changed: 2078 ins; 749 del; 400 mod
  Patch: https://git.openjdk.org/jdk/pull/21859.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21859/head:pull/21859

PR: https://git.openjdk.org/jdk/pull/21859