Process.waitFor() throws IllegalThreadStateException when a process returns an exit code of 259. As described in the bug report, `waitFor()` should be sensitive to the exit value. Previously, it erroneously threw IllegalStateException. Added a test to verify.
------------- Commit messages: - 8294899: Process.waitFor() throws IllegalThreadStateException Changes: https://git.openjdk.org/jdk/pull/10680/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10680&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8294899 Stats: 50 lines in 2 files changed: 49 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/10680.diff Fetch: git fetch https://git.openjdk.org/jdk pull/10680/head:pull/10680 PR: https://git.openjdk.org/jdk/pull/10680
