Merge pull request #2410 from Subv/sleepthread

Don't yield execution in SleepThread(0) if there are no available threads to run

src/core/hle/kernel/thread.cpp

@@ -508,6 +508,10 @@ SharedPtr<Thread> SetupMainThread(u32 entry_point, s32 priority) {
     return thread;
 }
 
+bool HaveReadyThreads() {
+    return ready_queue.get_first() != nullptr;
+}
+
 void Reschedule() {
     Thread* cur = GetCurrentThread();
     Thread* next = PopNextReadyThread();

src/core/hle/kernel/thread.h

@@ -218,6 +218,11 @@ private:
  */
 SharedPtr<Thread> SetupMainThread(u32 entry_point, s32 priority);
 
+/**
+ * Returns whether there are any threads that are ready to run.
+ */
+bool HaveReadyThreads();
+
 /**
  * Reschedules to the next available thread (call after current thread is suspended)
  */