dispatch: host declaration of `dispatch_pthread_root_queue_observer_h…

…ooks_s` This type is referenced before the declaration. This hoists the declaration earlier to have the type available when used.

src/queue_internal.h

@@ -445,6 +445,13 @@ DISPATCH_OPTIONS(dispatch_queue_flags, uint32_t,
 #pragma mark -
 #pragma mark dispatch_queue_t
 
+typedef struct dispatch_pthread_root_queue_observer_hooks_s {
+void (*queue_will_execute)(dispatch_queue_t queue);
+void (*queue_did_execute)(dispatch_queue_t queue);
+} dispatch_pthread_root_queue_observer_hooks_s;
+typedef dispatch_pthread_root_queue_observer_hooks_s
+*dispatch_pthread_root_queue_observer_hooks_t;
+
 typedef struct dispatch_queue_specific_s {
 const void *dqs_key;
 void *dqs_ctxt;
@@ -651,13 +658,6 @@ struct dispatch_queue_global_s {
 } DISPATCH_CACHELINE_ALIGN;
 
 
-typedef struct dispatch_pthread_root_queue_observer_hooks_s {
-void (*queue_will_execute)(dispatch_queue_t queue);
-void (*queue_did_execute)(dispatch_queue_t queue);
-} dispatch_pthread_root_queue_observer_hooks_s;
-typedef dispatch_pthread_root_queue_observer_hooks_s
-*dispatch_pthread_root_queue_observer_hooks_t;
-
 #ifdef __APPLE__
 #define DISPATCH_IOHID_SPI 1