• Polling watchers now check file sizes as well as "last modified" times, so
  they are less likely to miss changes on platforms with low resolution
  timestamps.
• DirectoryWatcher on Windows performance: reduce 100ms buffering of events
  before reporting to 5ms, the larger buffer isn't needed for correctness after
  the various fixes.
• DirectoryWatcher on Windows watches in a separate Isolate to make buffer
  exhaustion, "Directory watcher closed unexpectedly", much less likely. The old
  implementation which does not use a separate Isolate is available as
  DirectoryWatcher(path, runInIsolateOnWindows: false).
• DirectoryWatcher on Windows: if buffer exhaustion does happen, emit a
  "modify" event for all know files instead of an exception.
• Document behavior on Linux if the system watcher limit is hit.
• Require Dart SDK ^3.4.0.
• Bug fix: native DirectoryWatcher implementations now consistently handle
  links as files, instead of sometimes reading through them and sometimes
  reporting them as files. The polling DirectoryWatcher still reads through
  links.
• Bug fix: with the polling DirectoryWatcher, fix spurious modify event
  emitted because of a file delete during polling.
• Bug fix: due to the link handling change, native DirectoryWatcher on Linux
  and MacOS is no longer affected by a severe performance regression if there
  are symlink loops in the watched directory. The polling DirectoryWatcher
  is fixed to skip already-visited directories to prevent the performance issue
  while still reading through links.
• Bug fix: with DirectoryWatcher on Windows, the last of a rapid sequence of
  modifications in a newly-created directory was sometimes dropped. Make it
  reliably report the last modification.
• Bug fix: with DirectoryWatcher on Windows, a move over an existing file was
  reported incorrectly. For example, if a and b already exist, then a is
  moved onto b, it would be reported as three events: delete a, delete b,
  create b. Now it's reported as two events: delete a, modify b. This
  matches the behavior of the Linux and MacOS watchers.
• Bug fix: with DirectoryWatcher on Windows, new links to directories were
  sometimes incorrectly handled as actual directories. Now they are reported
  as files, matching the behavior of the Linux and MacOS watchers.
• Bug fix: unify DirectoryWatcher implementation on Windows with the MacOS
  implementation, addressing various race conditions around directory renames.
• Bug fix: new DirectoryWatcher implementation on Linux that fixes various
  issues: tracking failure following subdirectory move, incorrect events when
  there are changes in a recently-moved subdirectory, incorrect events due to
  various situations involving subdirectory moves.
• Bug fix: new DirectoryWatcher implementation on MacOS that fixes various
  issues including duplicate events for changes in new directories, incorrect
  events when close together directory renames have overlapping names.
• Bug fix: with FileWatcher on MacOS, a modify event was sometimes reported if
  the file was created immediately before the watcher was created. Now, if the
  file exists when the watcher is created then this modify event is not sent.
  This matches the Linux native and polling (Windows) watchers.