fix: panic: assignment to entry in nil map

kqueue.go

@@ -52,6 +52,9 @@ func NewWatcher() (*Watcher, error) {
 		kq:              kq,
 		closepipe:       closepipe,
 		watches:         make(map[string]int),
+		dirFlags:        make(map[string]uint32),
+		paths:           make(map[int]pathInfo),
+		fileExists:      make(map[string]bool),
 		externalWatches: make(map[string]bool),
 		Events:          make(chan Event),
 		Errors:          make(chan error),