If a move has matching target/destination, signal the event as create or delete.

runtime/bin/file_system_watcher_linux.cc

Index: runtime/bin/file_system_watcher_linux.cc
diff --git a/runtime/bin/file_system_watcher_linux.cc b/runtime/bin/file_system_watcher_linux.cc
index da5dee1ec77b56592c766ca363cac64fa9fa17d9..7cfb28eb161ae88b85d080035d9dd70af2a6ab4f 100644
--- a/runtime/bin/file_system_watcher_linux.cc
+++ b/runtime/bin/file_system_watcher_linux.cc
@@ -63,7 +63,7 @@ Dart_Handle FileSystemWatcher::ReadEvents(intptr_t id) {
   while (offset < bytes) {
     struct inotify_event* e =
         reinterpret_cast<struct inotify_event*>(buffer + offset);
-    Dart_Handle event = Dart_NewList(3);
+    Dart_Handle event = Dart_NewList(4);
     int mask = 0;
     if (e->mask & IN_MODIFY) mask |= kModifyContent;
     if (e->mask & IN_ATTRIB) mask |= kModefyAttribute;
@@ -79,6 +79,7 @@ Dart_Handle FileSystemWatcher::ReadEvents(intptr_t id) {
     } else {
       Dart_ListSetAt(event, 2, Dart_Null());
     }
+    Dart_ListSetAt(event, 3, Dart_NewBoolean(e->mask & IN_MOVED_TO));
     Dart_ListSetAt(events, i, event);
     i++;
     offset += kEventSize + e->len;