[input] Make device add/remove events broadcast

It proved necessary to support broadcasting events to all event
handlers, with device add/remove being the first such events.

include/QF/input/event.h

@@ -71,6 +71,11 @@ typedef enum {
 	ie_button,
 } IE_event_type;
 
+#define IE_broadcast_events (0 \
+		| (1 << ie_add_device) \
+		| (1 << ie_remove_device) \
+	)
+
 typedef struct {
 	IE_event_type type;
 	uint64_t    when;

libs/input/in_event.c

@@ -54,6 +54,16 @@ static unsigned focus;
 int
 IE_Send_Event (const IE_event_t *event)
 {
+	if ((1 << event->type) & IE_broadcast_events) {
+		for (size_t i = 0; i < ie_handlers.size; i++) {
+			ie_reghandler_t *reg = &ie_handlers.a[i];
+			if (reg->handler) {
+				reg->handler (event, reg->data);
+			}
+		}
+		return 1;
+	}
+
 	if (focus < ie_handlers.size && ie_handlers.a[focus].handler) {
 		ie_reghandler_t *reg = &ie_handlers.a[focus];
 		return reg->handler (event, reg->data);