isWatchSupported property
Test if watch is supported on the current system.
OS X 10.6 and below is not supported.
Implementation
static bool get isWatchSupported {
  final IOOverrides? overrides = IOOverrides.current;
  if (overrides == null) {
    return _FileSystemWatcher.isSupported;
  }
  return overrides.fsWatchIsSupported();
}