Update classes in the java.desktop module to use the jdk.internal.util.OperatingSystem enum instead of the `os.name` system property to select OS specific behaviors.
------------- Commit messages: - Remove unused os.arch system property - Apply OperatingSystem enum instead of os.name to java.desktop module Changes: https://git.openjdk.org/jdk/pull/13213/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13213&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8304912 Stats: 105 lines in 15 files changed: 19 ins; 39 del; 47 mod Patch: https://git.openjdk.org/jdk/pull/13213.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/13213/head:pull/13213 PR: https://git.openjdk.org/jdk/pull/13213
