RFR: 8342869: Errors related to unused code on Windows after 8339120 in awt

[Julian Waters]

After 8339120, gcc began catching many different instances of unused code in the Windows specific codebase. Some of these seem to be bugs. I've taken the effort to mark out all the relevant globals and locals that trigger the unused warnings and addressed all of them by commenting out the code as appropriate. I am confident that in many cases this simplistic approach of commenting out code does not fix the underlying issue, and the warning actually found a bug that should be fixed. In these instances, I will be aiming to fix these bugs with help from reviewers, so I recommend anyone reviewing who knows more about the code than I do to see whether there is indeed a bug that needs fixing in a different way than what I did

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Commit messages:
 - 8342869

Changes: https://git.openjdk.org/jdk/pull/21655/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21655&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8342869
  Stats: 19 lines in 8 files changed: 5 ins; 1 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/21655.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21655/head:pull/21655

PR: https://git.openjdk.org/jdk/pull/21655