When asked to monitor a file (not a directory), we often need to instead
monitor the parent directory to receive FS events. For example, when a
symbolic link is deleted/created, we don't receive any events unless we
are watching the parent.
The test currently watches /tmp, which the OS can create/modify files
under at any time outside of our control. So just ignore events that we
aren't interested in.
Also test removing an item from the FileWatcher.
This implements FileWatcher using inotify filesystem events. Serenity's
InodeWatcher is remarkably similar to inotify, so this is almost an
identical implementation.
The existing TestLibCoreFileWatcher test is added to Lagom (currently
just for Linux).
This does not implement BlockingFileWatcher as that is currently not
used anywhere but on Serenity.
This patch adds some rudimentary tests for InodeWatcher. It tests the
basic functionality, but maybe there are corner cases I haven't caught.
Additionally, this is our first LibCore test. :^)
