RFR: 8352970: Remove unnecessary Windows version check in Win32ShellFolderManager2

[Daniel Gredler]

Win32ShellFolderManager2 contains a check as to whether the current Windows version is Windows 2000 or later. The current minimum supported version is Windows 10, so this is no longer needed.

No test seems to currently exercise this code, and it's not easy to reliably test, but I've added a basic test that should surface any fundamental issues. The change is very simple, though.

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Commit messages:
 - Remove unnecessary Windows version check in Win32ShellFolderManager2

Changes: https://git.openjdk.org/jdk/pull/24256/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24256&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352970
  Stats: 59 lines in 2 files changed: 57 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24256.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24256/head:pull/24256

PR: https://git.openjdk.org/jdk/pull/24256