Removed duplicate case and incorrect setting of `isCygwin` for MSys/MinGW. --------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai).
------------- Commit messages: - Remove duplicate case and incorrect setting of `isCygwin` for MSys/MinGW Changes: https://git.openjdk.org/jdk/pull/31618/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=31618&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8387044 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/31618.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/31618/head:pull/31618 PR: https://git.openjdk.org/jdk/pull/31618
